To see the other types of publications on this topic, follow the link: Parasitic plants Mistletoes Mistletoes Parasitic plants.
Journal articles on the topic 'Parasitic plants Mistletoes Mistletoes Parasitic plants'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Parasitic plants Mistletoes Mistletoes Parasitic plants.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Mathiasen, Robert. "Susceptibility of Conifers to Three Dwarf Mistletoes in the Klamath-Siskiyou Mountains." Western Journal of Applied Forestry 26, no. 1 (January 1, 2011): 13–18. http://dx.doi.org/10.1093/wjaf/26.1.13.
Full textAbstract:
Abstract Dwarf mistletoes (Arceuthobium spp., Viscaceae) are parasitic flowering plants that infect members of the Pinaceae family in the western United States. This article reports additional host susceptibility data for three dwarf mistletoes found in the Klamath-Siskiyou Mountains of southwestern Oregon and northwestern California. Three mixed conifer stands, each infested with either mountain hemlock dwarf mistletoe, western white pine dwarf mistletoe, or Wiens' dwarf mistletoe (nine stands total) were sampled to evaluate the susceptibility of conifers to these parasites. At each of the study sites, 10–20 temporary circular plots with a 6-m radius (0.012 ha) were established around large, severely infected trees. Within plots, species, dbh, and dwarf mistletoe rating (six-class system) were determined for each live tree. On the basis of the incidence of infection, conifers were assigned to host susceptibility classes. Western white pine and mountain hemlock were principal hosts of western white pine and mountain hemlock dwarf mistletoes, respectively. Brewer spruce and red fir were principal hosts of Wiens' dwarf mistletoe. Other conifers sampled were less susceptible to these mistletoes. This information can be used by forest managers to mitigate the damage associated with infestations of these dwarf mistletoes in mixed conifer forests of the Klamath-Siskiyou Mountains.
2
Pritchard, Kyle R., Joan C. Hagar, and David C. Shaw. "Oak mistletoe (Phoradendron villosum) is linked to microhabitat availability and avian diversity in Oregon white oak (Quercus garryana) woodlands." Botany 95, no. 3 (March 2017): 283–94. http://dx.doi.org/10.1139/cjb-2016-0249.
Full textAbstract:
Mistletoes are parasitic or hemiparasitic flowering plants that parasitize woody plants around the globe. Important food and cover resources provided by mistletoes have been related to strong patterns of positive association between wildlife diversity and mistletoe density. Mistletoes also create microhabitat features known to be important to wildlife by causing deformations in their host trees. However, links between availability of mistletoe-formed microhabitat and wildlife diversity has not been well-studied. We investigated this relationship by quantifying microhabitat features and avian abundance and diversity related to infection by oak mistletoe (Phoradendron villosum (Nutt.) Nutt. ex Engelm.) in Oregon white oak (Quercus garryana Douglas ex Hook.). Quercus garryana woodlands support several avian species of conservation concern, so understanding the influence of mistletoe on wildlife habitat is critical. Our results suggest that (i) structural heterogeneity within tree crowns is positively associated with mistletoe load; (ii) avian species richness and abundance are positively associated with mistletoe load; and (iii) the fruit of P. villosum is an important food for Western Bluebird (Sialia mexicana) and other wildlife in late autumn and early winter. If a goal of restoration is to maintain habitat for oak-associated bird species, managers should consider the retention of some oaks hosting mistletoe.
3
Scalon, Marina Corrêa, Sabrina Alves dos Reis, and Davi Rodrigo Rossatto. "Shifting from acquisitive to conservative: the effects of Phoradendron affine (Santalaceae) infection in leaf morpho-physiological traits of a Neotropical tree species." Australian Journal of Botany 65, no. 1 (2017): 31. http://dx.doi.org/10.1071/bt16177.
Full textAbstract:
Mistletoes are parasitic plants that penetrate the host branches through a modified root and connect to their xylem to acquire nutrients and water. Under mistletoe infection, resources that would otherwise be used by the host are stolen by the parasite. Our aim was to compare leaf morpho-physiological traits between healthy uninfected branches and mistletoe-infected branches of a Neotropical tree species (Handroanthus chrysotrichus (Mart. ex DC.) Mattos – Bignoniaceae). We also investigated differences between mistletoe and host leaf traits. Morphological (petiole length and thickness, leaf area and thickness, and specific leaf area) and physiological leaf traits (pre-dawn and midday water potential) were measured in 10 individuals infected with the mistletoe Phoradendron affine (Pohl ex DC.) Engl. & K.Krause (Santalaceae). Mistletoes showed smaller and thicker leaves with lower pre-dawn and midday water potential, suggesting that mistletoes are more profligate water users than the host. Host leaves from infected branches were scleromorphic and showed stronger water-use control (less negative water potential) than host leaves from uninfected branches. Our results indicated that leaves from infected branches shifted to a more conservative resource-use strategy as a response to a water and nutrient imbalance caused by mistletoe infection.
4
Fontúrbel, Francisco E. "Mistletoes in a changing world: a premonition of a non-analog future?" Botany 98, no. 9 (September 2020): 479–88. http://dx.doi.org/10.1139/cjb-2019-0195.
Full textAbstract:
Mistletoes are a group of flowering plants that have developed a parasitic lifeform through complex eco-evolutionary processes. Despite being considered a pest, mistletoes represent a keystone forest resource and are involved in complex plant–plant and plant–animal interactions. Their parasitic lifeform and specialized ecological interactions make mistletoes an ideal model with which to understand the effects of anthropogenic disturbances in a changing world. The accelerated growth of the human population has altered all ecosystems on Earth, leading to biodiversity loss. Land-use changes (involving habitat loss, fragmentation, degradation, and transformation processes) can alter the ecological scenario for mistletoe by altering hosts, mutualists, and nutrient cycling. Those changes may have large consequences at the community level, changing the spatial structure of mistletoes, as well as interaction effectiveness, facilitation process, interaction disruption, and novel interactions with invasive species, leading to non-analog communities in the long run. Furthermore, climate change effects operate on a global scale, enhancing the effects of land-use changes. As temperatures increase, many species would alter their distribution and phenology, potentially causing spatial and temporal mismatches. But more critical is the fact that water stress is likely to disrupt key ecological interactions. Thus, mistletoes can provide valuable insights for what we can expect in the future, as a result of human disturbances.
5
Okubamichael, Desale Y., Megan E. Griffiths, and David Ward. "Host specificity in parasitic plants—perspectives from mistletoes." AoB Plants 8 (2016): plw069. http://dx.doi.org/10.1093/aobpla/plw069.
Full text
6
Glatzel, G., and B. W. Geils. "Mistletoe ecophysiology: host–parasite interactionsThis review is one of a collection of papers based on a presentation from the Stem and Shoot Fungal Pathogens and Parasitic Plants: the Values of Biological Diversity session of the XXII International Union of Forestry Research Organization World Congress meeting held in Brisbane, Queensland, Australia, in 2005." Botany 87, no. 1 (January 2009): 10–15. http://dx.doi.org/10.1139/b08-096.
Full textAbstract:
Mistletoes are highly specialized perennial flowering plants adapted to parasitic life on aerial parts of their hosts. In our discussion on the physiological interactions between parasite and host, we focus on water relations, mineral nutrition, and the effect of host vigour. When host photosynthesis is greatest, the xylem water potential of the host is most negative. To maintain a flux gradient and avoid stomatal closure and wilting, the mistletoe must tolerate a more negative water potential than the host. Succulent leaves enhance water storage and allow mistletoes to rehydrate before their hosts rehydrate. Mistletoe infections may disrupt the host stomatal control system, causing early and oscillating closure of host stomata, thereby diminishing host photosynthetic gain. Mistletoes lack the active uptake of minerals of a typical plant root system and rely upon the haustorium to connect with the host for the essentially one-way flow of photosynthates and nutrients from host to parasite. Modest growth rates, tolerance, succulence, and rapid leaf turnover are some means by which mistletoes avoid mineral deficiency or excess. We propose high concentrations of some mobile elements in the mistletoe by comparison with the host result not from active uptake, but from the inevitable accumulation by a parasite that utilizes host phloem sap. The relationship between host condition and mistletoe performance varies by situation and over time. In some cases, the host can outgrow the mistletoe, but favorable host status can also accelerate mistletoe growth. A better understanding of the mistletoe–host interaction can be utilized in improved management of infested forest plantations for resource production as well as for conservation of biodiversity and endangered species.
7
Madibela, O. R., M. Letso, B. Makoba, and O. Seitshiro. "Chemical composition and in vitro dry matter digestibility of parasitic plants reflect that of indigenous browse trees." Proceedings of the British Society of Animal Science 2003 (2003): 173. http://dx.doi.org/10.1017/s1752756200013326.
Full textAbstract:
Mistletoes are common parasitic plants that attach on branches of Acacia species, Boscia albitrunca, Ziziphus mucronata and other trees of semi-arid Botswana. These plants form an interesting alternative and additional feed resource, which could increase both mineral and protein intake of ruminants. Previous studies (Madibela et al., 2000, 2002) have shown that these parasitic plants have high crude protein and mineral levels than what is expected of natural grasses. The hypothesis is that the higher the nutritive value of host browse trees the higher it is in the parasitic plants.
8
Watson, David M., and Matthew Herring. "Mistletoe as a keystone resource: an experimental test." Proceedings of the Royal Society B: Biological Sciences 279, no. 1743 (July 11, 2012): 3853–60. http://dx.doi.org/10.1098/rspb.2012.0856.
Full textAbstract:
Various entities have been designated keystone resources, but few tests have been attempted and we are unaware of any experimental manipulations of purported keystone resources. Mistletoes (Loranthaceae) provide structural and nutritional resources within canopies, and their pervasive influence on diversity led to their designation as keystone resources. We quantified the effect of mistletoe on diversity with a woodland-scale experiment, comparing bird diversities before and after all mistletoe plants were removed from 17 treatment sites, with those of 11 control sites and 12 sites in which mistletoe was naturally absent. Three years after mistletoe removal, treatment woodlands lost, on average, 20.9 per cent of their total species richness, 26.5 per cent of woodland-dependent bird species and 34.8 per cent of their woodland-dependent residents, compared with moderate increases in control sites and no significant changes in mistletoe-free sites. Treatment sites lost greater proportions of birds recorded nesting in mistletoe, but changes in species recorded feeding on mistletoe did not differ from control sites. Having confirmed the status of mistletoe as a keystone resource, we suggest that nutrient enrichment via litter-fall is the main mechanism promoting species richness, driving small-scale heterogeneity in productivity and food availability for woodland animals. This explanation applies to other parasitic plants with high turnover of enriched leaves, and the community-scale influence of these plants is most apparent in low productivity systems.
9
Reid, Nick, and Simon F. Shamoun. "Contrasting research approaches to managing mistletoes in commercial forests and wooded pasturesThis minireview is one of a collection of papers based on a presentation from the Stem and Shoot Fungal Pathogens and Parasitic Plants: the Values of Biological Diversity session of the XXII International Union of Forestry Research Organization World Congress meeting held in Brisbane, Queensland, Australia, in 2005." Botany 87, no. 1 (January 2009): 1–9. http://dx.doi.org/10.1139/b08-109.
Full textAbstract:
Many mistletoe species are pests in agricultural and forest ecosystems throughout the world. Mistletoes are unusual “weeds” as they are generally endemic to areas where they achieve pest status and, therefore, classical biological control and broad-scale herbicidal control are usually impractical. In North American coniferous forests, dwarf mistletoe ( Arceuthobium spp.) infection results in major commercial losses and poses a public liability in recreation settings. Hyperparasitic fungi have potential as biological control agents of dwarf mistletoe, including species which attack shoots, berries, and the endophytic systems of dwarf mistletoe. Development of an inundative biological control strategy will be useful in situations where traditional silvicultural control is impractical or undesirable. In southern Australia, farm eucalypts are often attacked and killed by mistletoes ( Amyema spp.) in grazed landscapes where tree decline and biodiversity loss are major forms of land degradation. Although long-term strategies to achieve a balance between mistletoe and host abundance are promoted, many graziers want short-term options to treat severely infected trees. Recent research has revisited the efficiency and efficacy of silvicultural treatments and selective herbicides in appropriate situations. The results of recent research on these diverse management strategies in North America and Australia are summarized.
10
Bilgili, Ertugrul, Kadir Alperen Coskuner, and Murat Ozturk. "Leaf area – sapwood area relationship in Scots pine (Pinus sylvestris L.) under mistletoe (Viscum album ssp. austriacum) infection." Dendrobiology 84 (November 9, 2020): 1–11. http://dx.doi.org/10.12657/denbio.084.001.
Full textAbstract:
Leaf area is linearly correlated with sapwood area in trees. The linearity of this relationship can be affected by some biotic and abiotic factors. Mistletoes are hemi parasitic plants that take up water and mineral nutrients from their hosts and affect host physiological responses. There is no conclusive evidence to show the effect of pine mistletoe (Viscum album ssp. austriacum) on leaf area and sapwood area relationship in Scots pine trees (Pinus sylvestris L.) at tree level. The aim of this study is to determine and quantify the effect of pine mistletoe on the structural variation of leaf area and sapwood area relationship at tree level in Scots pine. A total of 18 mistletoe infected and 12 uninfected Scots pine trees were destructively sampled. All needles and mistletoes were completely removed from sampled trees to determine needle and mistletoe characteristics, biomass and leaf area. Sapwood areas at breast height (BH) and at crown base height (CBH) were determined from wood discs taken from BH (1.3m) and CBH. Sapwood area was delineated by benzidine staining method. Pearson correlation, t-test and regression analyses were conducted to determine the relationship between sapwood area and needle-mistletoe leaf area relationships. The results indicated that both the relationships between sapwood area and leaf area in uninfected, and sapwood area and total leaf area (needle plus mistletoe leaf only) in infected trees were linear. However, the slope of regression equation for mistletoe infected trees was considerably lower when compared to the uninfected trees. As for the variation of the sapwood area along the stem below live crown, there was a slight difference between sapwood area at BH and CBH. The study showed also that mistletoe infection led to a significant reduction in needle size (length, width, area and weight) in Scots pine trees. Significant relationships were found between the sapwood area and leaf area in this study. The results of this study may help fill the gap in the knowledge concerning the impacts of pine mistletoe on the dynamics of Scots pine trees.
11
Hutabarat, Prima Wahyu Kusuma, Rizmoon Nurul Zulkarnaen, and Melza Mulyani. "Keanekaragaman Benalu di Ecopark, Cibinong Science Center-Botanic Gardens." Al-Kauniyah: Jurnal Biologi 13, no. 2 (October 31, 2020): 263–77. http://dx.doi.org/10.15408/kauniyah.v13i2.15112.
Full textAbstract:
AbstrakArea konservasi ex situ, Ecopark Cibinong Science Center-Botanic Gardens (CSC-BG), membutuhkan strategi pemeliharaan tanaman koleksi yang tepat untuk mendukung kesehatan dan keberlanjutan koleksinya. Serangan benalu atau tumbuhan parasit tidak hanya dapat merusak estetika, namun juga menghambat pertumbuhan dan perkembangan, bahkan membunuh tanaman koleksi. Penelitian ini bertujuan untuk mengetahui keanekaragaman jenis benalu dan distribusi spasial dari sebaran benalu di Ecopark CSC-BG. Pengumpulan spesimen dan data, meliputi jenis dan jumlah benalu, jenis dan kondisi inang, habitat menggunakan metode jelajah di seluruh area ini. Ditemukan empat jenis benalu dari suku Lorantaceae, yaitu Dendrophthoe pentandra (L.) Miq., Scurrula atropurpurea (Blume) Danser, Macrosolen cochinchinensis (Lour.) Tiegh., dan Dendrophthoe sp. Benalu tersebut tersebar di bioregion Blok 1, Jawa-Bali, Kalimantan, Sumatra, dan Papua. Beberapa faktor ekofisiologi yang disarankan untuk diperhatikan dalam distribusi benalu adalah tinggi inang, ekspos cahaya pada tajuk bagian atas inang, kepadatan tanaman koleksi, keterbukaan atau ekspos cahaya matahari pada habitat. Indeks keanekaragaman (H’) dan indeks kemerataan (E’) benalu yang ditemukan menunjukkan H’ = 1,29 dan E’ = 0,93. Hasil analisis pola spasial, keberadaan benalu relatif merata di seluruh bagian Ecopark CSC-BG, dengan keragaman jenis tertinggi berada di bioregion Jawa-Bali, Sumatra, dan Kalimantan. Kesimpulan penelitian ini 4 jenis benalu yang ditemukan di Ecopark CSC-BG dengan nilai indeks keanekaragaman jenis benalu tergolong sedang dengan pola sebaran merata.AbstractThe Ecopark Cibinong Science Center-Botanic Gardens (CSC-BG), requires the right collection of plant maintenance strategies to support the health and sustainability of the collection. Attack by parasites or parasitic plants can not only destroy aesthetics, but also inhibit growth and development, and even kill the collected plants. This study aims to determine the diversity of parasite types and the spatial distribution of the distribution of parasites in Ecopark CSC-BG. Collection of specimens and data, including the type and number of parasites, types, and conditions of the host, habitat using the roaming method throughout this area. Four types of parasites were found from the Loranthaceae tribe, namely Dendrophthoe pentandra (L.) Miq., Scurrula atropurpurea (Blume) Danser, Macrosolen cochinchinensis (Lour.) Tiegh., and Dendrophthoe sp. These types of parasites are scattered in the Block 1 bioregion, Java-Bali, Kalimantan, Sumatra, and Papua. Some of the recommended ecophysiological factors to consider in the distribution of mistletoes were host height, light exposure to the upper canopy of the host, plant collection density, openness, or exposure to sunlight in the habitat. The diversity index (H') and evenness index (E') of mistletoes found were 1.29 and 0.93, respectively. The results of spatial pattern analysis, the presence of mistletoes was relatively evenly distributed throughout the garden, with the highest species diversity found in the Java-Bali, Sumatra, and Kalimantan Bioregions. This study concludes that there were 4 species of mistletoes found in Ecopark CSC-BG with a moderate diversity index and an even distribution pattern.
12
Buen, Lorena López-de, and Juan Francisco Ornelas. "Frugivorous birds, host selection and the mistletoe Psittacanthus schiedeanus, in central Veracruz, Mexico." Journal of Tropical Ecology 15, no. 3 (May 1999): 329–40. http://dx.doi.org/10.1017/s0266467499000851.
Full textAbstract:
Frugivorous birds play an important role in parasitic mistletoe transmission among host species. The foraging behaviour and host selection of Psittacanthus schiedeanus mistletoe fruit-eating birds was studied in cloud forest remnants in Central Veracruz, México. Cedar waxwings, Bombycilla cedrorum, gray silky-flycatchers, Ptilogonys cinereus, and social flycatchers, Myiozetetes similis, eating ripe whole mistletoe fruits and defecating or regurgitating the seeds were observed. That variation in host species selection by frugivorous birds had a direct effect on mistletoe dispersion was hypothesized. To test whether mistletoe host species are visited in proportion to their abundance (total number of trees), or infested-tree abundance (total number of infested trees), or abundance of mistletoes (total number of individual mistletoe plants in each host species), the number of trees, infested trees and individual mistletoe plants were recorded. Tree abundance, infested-tree abundance and mistletoe abundance were different among host species. Frequency of birds' visits to host species varied depending on the tree, infested-tree, or mistletoe abundance. Liquidambar styraciflua was the most abundant host species with the highest number of infested trees and individual mistletoe plants, but Persea americana and Crataegus mexicana host species had the highest number of individual mistletoe plants in each tree. Our data suggest that L. styraciflua was the most selected host species by the three frugivorous birds. Host selection by birds is one behavioural factor in explaining differences in prevalence among host species, and variation in infection levels among individuals of one host species.RESUMEN. Las aves frugívoras juegan un importante papel en la transmisión de muérdagos parásitos hacia sus árboles hospederos. La conducta de forrajeo y selección de hospedero de aves consumidoras de frutos del muérdago Psittacanthus schiedeanus fueron estudiados en remanentes de bosque mesófilo de montaña del Centro de Veracruz, México. Bombycilla cedrorum, Ptilogonys cinereus and Myiozetetes similis fueron observados consumiendo frutos maduros enteros y defecando o regurgitando las semillas. Hipotetizamos que la variación en la selección de la especie hospedera por las aves frugívoras tiene un efecto directo en la dispersión del muérdago. Para probar si las especies de árboles hospederos son visitadas en proporción a su abundancia (número total de árboles), o la abundancia de hospederos infectados (número de árboles infectados) o la abundancia de muérdagos (número total de plantas individuales de muérdago en una sola especie de árbol); el número de árboles, árboles infestados y plantas de muérdago fueron registradas. La abundancia de árboles, de árboles infestados y de plantas de muérdago fue diferente entre las especies de árboles estudiadas. La frecuencia de visitas de las aves a las especies hospederas varió de acuerdo a la abundancia de árboles, de árboles infestados y de plantas de muérdago. Liquidambar styraciflua fue la especie hospedera más abundante con el mayor número de árboles infestados y abundancia de muérdagos, pero las especies Persea americana y Crataegus mexicana presentaron el mayor número de plantas de múerdago por árbol. Nuestros datos sugieren que L. styraciflua fue la especie hospedera más seleccionada por las aves frugívoras. La selección de hospederos por las aves es uno de los factores conductuales que explican las diferencias en prevalencia entre especies de hospedero, y la variación en los niveles de infestación entre individuos de una de las especies de hospedero.
13
Kuo, John, and John S. Pate. "Anatomy and ultrastructure of haustoria in selected West Australian parasitic angiosperms." Proceedings, annual meeting, Electron Microscopy Society of America 48, no. 3 (August 12, 1990): 690–91. http://dx.doi.org/10.1017/s042482010016100x.
Full textAbstract:
Our understanding of nutrient transfer between host and flowering parasitic plants is usually based mainly on physiological concepts, with little information on haustorial structure related to function. The aim of this paper is to study the haustorial interface and possible pathways of water and solute transfer between a number of host and parasites.Haustorial tissues were fixed in glutaraldehyde and embedded in glycol methacrylate (LM), or fixed in glutaraldehyde then OsO4 and embedded in Spurr’s resin (TEM).Our study shows that lumen to lumen continuity occurs between tracheary elements of a host and four S.W. Australian species of aerial mistletoes (Fig. 1), and some root hemiparasites (Exocarpos spp. and Anthobolus foveolatus) (Fig. 2). On the other hand, haustorial interfaces of the root hemiparasites Olax phyllanthi and Santalum (2 species) are comprised mainly of parenchyma, as opposed to terminating tracheads or vessels, implying that direct solution transfer between partners via vessels or tracheary elements may be limited (Fig. 3).
14
Ziegler, Dylan J., and Cynthia Ross Friedman. "Vegetative and floral development in the pistillate plant of Arceuthobium americanum (lodgepole pine dwarf mistletoe): an environmental scanning electron microscopy study of its phenology and shoot organization." Botany 95, no. 3 (March 2017): 337–46. http://dx.doi.org/10.1139/cjb-2016-0253.
Full textAbstract:
Dwarf mistletoes (DM), genus Arceuthobium, are dioecious parasitic flowering plants having prolonged life cycles lasting six years, culminating with explosive discharge of the single seed from the fruit. Arceuthobium americanum Nutt. ex Engelm., the lodgepole pine dwarf mistletoe, infects lodgepole pine (Pinus contorta subsp. latifolia (Engelm.) Critchfield) in western North America, compromising the forest economy. Highly reduced flowers appear no later than two years following shoot development, with female flowers appearing and persisting for over two years. Development of the pistillate plant, including initiation of floral growth, has not been fully explored. Here, we used environmental scanning electron microscopy to demark phenological waypoints throughout the pistillate plant’s development. As successive crops of female flowers emerged every year, up to three generations of flowers/fruit could be found on a single shoot in late summer; we used these three generations to delineate specific developmental stages. Vegetative shoots could initiate growth at any time within the growing season, could assume a terminal position, could also adopt sympodial branching, but were never whorled or adventitious. Floral branches, however, could initiate adventitiously from older nodes in a whorled pattern, and could house flowers/fruits of any generation. Vegetative and floral units were structurally homogeneous, suggesting shared developmental pathways.
15
Wilson, Carol A., and Clyde L. Calvin. "Metadata provide insights on patterns of epiparasitism in mistletoes (Santalales), an overlooked topic in forest biology." Botany 95, no. 3 (March 2017): 259–69. http://dx.doi.org/10.1139/cjb-2016-0264.
Full textAbstract:
Mistletoes are aerial-branch parasites belonging to one of five families in the Santalales. Usually, mistletoe hosts are autotrophic, but if the hosts themselves are parasitic, the plant parasitizing the host is an epiparasite. Three categories of epiparasites are recognized, chance-, obligate-, and auto-epiparasites. Loranthaceae and Viscaceae comprise about 97% of mistletoe species and also the largest number of epiparasites. We report frequencies and biogeographical distributions of epiparasite – parasite host combinations for Loranthaceae and Viscaceae, and we summarize epiparasitism in other mistletoe families. Parasitic hosts are primarily recruited from Loranthaceae, whereas most epiparasites are members of Viscaceae. Twenty-seven species are considered likely to be obligate epiparasites. Data suggest species abundance influences whether mistletoes serve as host to other mistletoes. We found no reports of epiparasitism in Misodendraceae and only a few reports for Santalaceae, although Santalaceae are often root-parasitic hosts. In Phacellaria (Amphorogynaceae) all species are obligate epiparasites, mainly on Loranthaceae. Epiparasitism occurs worldwide and is most common in the tropics and subtropics. The greatest number of reports is from Oceania, the smallest from Africa. Epiparasitism in mistletoes has received little research attention, yet our research shows that this life form contributes to species and structural diversity in forest ecosystems across the globe.
16
Mourão, Fabiana Alves, Claudia Maria Jacobi, José Eugênio Côrtes Figueira, and Eugênia Kelly Luciano Batista. "Effects of the parasitism of Struthanthus flexicaulis (Mart.) Mart. (Loranthaceae) on the fitness of Mimosa calodendron Mart. (Fabaceae), an endemic shrub from rupestrian fields over ironstone outcrops, Minas Gerais State, Brazil." Acta Botanica Brasilica 23, no. 3 (September 2009): 820–25. http://dx.doi.org/10.1590/s0102-33062009000300023.
Full textAbstract:
Parasitic plants (mistletoes) may alter the growth, reproduction and physiology of their hosts. Mimosa calodendron (Fabaceae) is a legume abundant in rupestrian fields on ironstone outcrops, frequently attacked by the hemiparasite Struthanthus flexicaulis (Loranthaceae). The objective of this study was to evaluate the consequences of parasitism by S. flexicaulis on the fitness of M. calodendron. The intensity of parasitism and mortality on hosts of different sizes was evaluated, and foliage cover, fruit and seed set in parasitized and non-parasitized individuals were compared. More than 65% of a population of 1820 individuals was attacked. Host density positively influenced parasitism. The mortality and number of attacked hosts increased with their crown diameter. Heavily parasitized individuals showed 75 to 95% reduction of leaf cover and fruit production of 25% of those non-parasitized. Although no statistical difference was detected between the number of seeds per fruit, seed weight was lower in attacked plants. Parasitism by S. flexicaulis on M. calodendron may alter its population structure and dynamics, by reducing survival and fecundity rates.
17
Carnegie, Angus J., Huiquan Bi, Scott Arnold, Yun Li, and Doug Binns. "Distribution, host preference, and impact of parasitic mistletoes (Loranthaceae) in young eucalypt plantations in New South Wales, AustraliaThis article is one of a collection of papers based on a presentation from the Stem and Shoot Fungal Pathogens and Parasitic Plants: the Values of Biological Diversity session of the XXII International Union of Forestry Research Organization World Congress meeting held in Brisbane, Queensland, Australia, in 2005." Botany 87, no. 1 (January 2009): 49–63. http://dx.doi.org/10.1139/b08-127.
Full textAbstract:
Mistletoe is a common sight in mature eucalypt trees in Australia, especially in remnant stands in agricultural and pastoral areas, where they have been associated with debility and death. We surveyed over 450 eucalypt plantations in New South Wales, Australia, for mistletoe, and report for the first time that mistletoe infestation is becoming a problem in young eucalypt plantations. Forty-three plantations were infected, but only 9 of these had levels of mistletoe of 20% or more trees infected; 4 had levels of 38%, 40%, 65%, and 68%. Mistletoe was observed in plantations ranging in age from 3–10 years old. Species of Corymbia ( Corymbia maculata (Hook.) K.D. Hill & L.A.S. Johnson and Corymbia citriodora subsp. variegata (F. Muell.) K.D. Hill & L.A.S. Johnson) were the most susceptible to mistletoe. The mistletoe species Dendrophthoe vitellina (F. Muell.) Tiegh. was commonly observed in plantations in both lower and upper northeast New South Wales, while Amyema bifurcata (Benth.) Tiegh. was only observed in the upper northeast. We observed a significant impact on growth of mistletoe, affecting tree growth as young as four years old. Simulated analysis indicated that mistletoe infection can reduce stand basal area by 10% and stand volume by 13%. However, the impact of mistletoe on tree growth was variable across space and time.
18
., Sunaryo, and Tahan Uji. "KEANEKARAGAMAN JENIS BENALU PEMARASIT PADA TANAMAN DI KEBUN RAYA BATURRADEN DAN SEKITARNYA." Jurnal Teknologi Lingkungan 11, no. 2 (December 2, 2016): 205. http://dx.doi.org/10.29122/jtl.v11i2.1204.
Full textAbstract:
Benalu is one of the parasitic plant group which have been ataccked to many plantsspecies in Baturraden Botanical Garden and its vacinity. Exploration and collection of parasitic plants species in this area are conducted. Five parasitic plants species, i.e.Dendropthoe curvata, Dendropthoe pentandra, Macrosolen cochinchinensis, Scurrula lepidota and Scurrula parasitica are recorded to parasiting 18 plants species in this area. Dendropthoe pentandra is reported as the highest population species to parasiting plants species. While the plants species of Myrtaceae and Lauraceae families are also reported as the highest species parasited.Key words : diversity – mistletoe – Baturraden Botanic Garden and its vacinity
19
Paine, Laura K., and Helen C. Harrison. "Mistletoe: Its Role in Horticulture and Human Life." HortTechnology 2, no. 3 (July 1992): 324–30. http://dx.doi.org/10.21273/horttech.2.3.324.
Full textAbstract:
Parasitic flowering plants represent a unique ecological adaptation, having evolved away from independent function and toward an increasing dependence on other higher plants for survival. Mistletoe, a common evergreen parasite of woody plants, has played a significant role in human culture for centuries. Throughout history, mistletoe species were nurtured and revered as medicinal herbs and religious symbols. But the role of mistletoe has changed. Its importance in western culture has dwindled to a minor, though enduring, association with the Christmas holiday. In contrast, its significance as a parasite of tree crops and woody ornamentals has increased in recent years. Mistletoe species are studied in efforts to control their pathogenic effects and to gain insight into the evolutionary role played by this family of parasitic flowering plants. The unique characteristics of mistletoe that challenge horticultural researchers have contributed to its enduring role in human life.
20
Rana, Santosh Kumar, and Hum Kala Rana. "People’s perception on parasitic plants : helping humans, harming plants?" International Journal of Biological Research 4, no. 2 (September 26, 2016): 215. http://dx.doi.org/10.14419/ijbr.v4i2.6640.
Full textAbstract:
Parasitic plants have a rich ethnobotanical heritage in Nepal. They are harvested for use in medicine, traded as material and invoked during a variety of rituals by practitioners from the low plains to the high Himalayas. However in spite of their local importance, these plant species have received little attention from ethno-biologists due to their unique, often misunderstood, biology. This study seeks to expand the current ethnobotanical knowledge by not only documenting Nepal’s parasitic flora but by also providing insight into how these plants are used and perceived in Nepal’s biologically and culturally diverse environment. Ethnobotanical data for this research was collected using the Participatory Rural Appraisal (PRA) and Rapid Rural Appraisal (RRA) methods among 52 respondents from different ethnic groups of Nepal (4 districts). A total of 20 plants species from five parasitic families were recorded and identified as ethnobotanical uses. They are 13 species of Mistletoe, 3 species of Dodder with 1 variety, 2 species in Balanophoraceae and 1 species in Orobanchaceae. The perceived knowledge of indigenous people led to the hypothesis Doctrine of Signature. With this information, Nepal’s burgeoning state can begin targeting and managing these plant species through agricultural, community forestry and conservation policy.
21
Mathiasen, R., A. Flores, H. Miranda, and L. Cadio. "First Report of Arceuthobium vaginatum subsp. vaginatum on Pinus pseudostrobus." Plant Disease 88, no. 9 (September 2004): 1046. http://dx.doi.org/10.1094/pdis.2004.88.9.1046b.
Full textAbstract:
Arceuthobium vaginatum (Willd.) Presl subsp. vaginatum (family Viscaceae) is the most widespread and common dwarf mistletoe in Mexico (2). Although most dwarf mistletoes are considered to be relatively host-specific parasites, this species has the broadest host range found in the genus. It has been reported to infect 13 species of pines (Pinus spp., family Pinaceae) (2). Pinus pseudostrobus Lindl. is a common pine within the geographic range of A. vaginatum and has been reported as possibly being immune to this mistletoe (2). However, we have found a location in the Sierra Madre Oriental, Nuevo Leon, Mexico where A. vaginatum subsp. vaginatum is severely parasitizing P. pseudostrobus. The stand of infected P. pseudostrobus is located approximately 3 km east of Laguna de Sanchez(25°19′42″N, 100°15′45″W, elevation 1,950 m). Several hundred P. pseudostrobus are infected at this location; several trees in the stand have one or more dwarf mistletoe infections on nearly every branch and many trees have bole infections. P. pseudostrobus is the only pine growing at this locality, and the extent of infection on this pine clearly indicates it is highly susceptible to A. vaginatum subsp. vaginatum. Hawksworth and Wiens (2) based their tentative classification of P. pseudostrobus as immune to A. vaginatum subsp. vaginatum on observations of uninfected P. pseudostrobus growing near severely infected pines in central Mexico. The discrepancy between the susceptibility of P. pseudostrobus in central Mexico and in Nuevo Leon may be related to the different taxonomic classifications afforded these populations by different pine taxonomists. For example, Perry (3) considers the populations of P. pseudostrobus growing in Nuevo Leon to represent P. pseudostrobus forma megacarpa Loock, while Farjon and Styles (1) treat these populations as typical P. pseudostrobus. Whether the high level of susceptibility of the P. pseudostrobus population near Laguna de Sanchez indicates these populations are taxonomically distinct from typical P. pseudostrobus needs further study, but the severe infection we observed in Nuevo Leon clearly demonstrates that P. pseudostrobus should be reclassified as a principal host of A. vaginatum subsp. vaginatum in northeastern Mexico. Specimens of A. vaginatum subsp. vaginatum on P. pseudostrobus have been deposited at the Deaver Herbarium, Northern Arizona University, Flagstaff (Accession No. 76455). To our knowledge, this is the first report of A. vaginatum subsp. vaginatum on P. pseudostrobus. It should also be noted that the population of A. vaginatum subsp. vaginatum near Laguna de Sanchez is 150 m below the lower elevation limit previously reported for this dwarf mistletoe in Mexico (2). References: (1) A. Farjon and B. Styles. Pinus (Pinaceae). Flora Neotropica, Monogr. 75. NY Bot. Gard., 1997. (2) F. Hawksworth and D. Wiens. Dwarf mistletoes: Biology, pathology, and systematics. USDA For. Serv. Agric. Handb. 709, 1996. (3) J. P. Perry. The Pines of Mexico and Central America. Timber Press, Portland, OR, 1991.
22
Qasem, Jamal R. "An Updated Inventory of Mistletoe (Plicosepalus acaciae and Viscum cruciatum) Distribution in Jordan, Hosts, and Severity of Infestation." Weed Technology 23, no. 3 (September 2009): 465–69. http://dx.doi.org/10.1614/wt-08-079.1.
Full textAbstract:
A botanical survey conducted from 2003 to 2007 showed the occurrence of the acacia strap flower and the Oriental mistletoe plant in different regions in Jordan. Acacia strap flower was found parasitizing 26 plant species belonging to 12 families. Oriental mistletoe attacked 14 plant species from eight families. Parasitized species ranged from wild shrubs to fruit and forest trees. Eleven Fabaceae species were parasitized by acacia strap flower, whereas Oriental mistletoe parasitized six Rosaceae species. Caper, pomegranate, white weeping broom, and white willow were attacked by both parasites. Infection by both parasites resulted in mortality of host plants in many cases. Hosts severely attacked by acacia strap flower were African jujube, Australian pine, chinaberry, Christ thorn jujube, common jujube, oleander, poinciana, sumac, tamarisk, terebinth, and white weeping broom. Oriental mistletoe heavily parasitized almond, mosphilla, olive, Palestine buckthorn, pomegranate, and white weeping broom. Results indicated the high potential of both parasites to spread and attack new hosts in the absence of control measures.
23
Parker, Chris. "Parasitic Weeds: A World Challenge." Weed Science 60, no. 2 (June 2012): 269–76. http://dx.doi.org/10.1614/ws-d-11-00068.1.
Full textAbstract:
While witchweed is nearing eradication in the United States, it continues to thrive in other parts of the world, especially in Africa, together with other witchweed species. The continuing problems from witchweeds and other parasitic weeds, the broomrapes, dodders and mistletoes, are outlined, including their extent, the degrees of damage caused, and the difficulties in their control. While a small minority are being successfully controlled by the use of immune varieties, most are currently controlled by existing techniques only partially, or on a local basis, and they may even be spreading or intensifying. The challenges they present are emphasised.
24
Richter, A., M. Popp, R. Mensen, GR Stewart, and DJV Willert. "Heterotrophic Carbon Gain of the Parasitic Angiosperm Tapinanthus oleifolius." Functional Plant Biology 22, no. 4 (1995): 537. http://dx.doi.org/10.1071/pp9950537.
Full textAbstract:
Tapinanthus oleifolius is a xylem-tapping mistletoe, parasitising a wide range of host trees including acacias, which are potentially nitrogen fixing, and Euphorbia virosa, which acquires CO2 mainly by nocturnal fixation via phosphoenolpyruvate carboxylase. Heterotrophic carbon gain by T. oleifolius was estimated by two different approaches. Firstly, δ13C values of leaves were calculated from cI/ca values and compared with measured δ13C ratios of these leaves and corresponding host xylem saps. Secondly, carbon intake from the host was determined by measuring carbon content of the host xylem sap and transpiration of the mistletoe leaves. This taken together with the photosynthetic CO2 net uptake allowed the calculation of a carbon budget and hence the proportion of heterotrophically-derived carbon. There was good agreement between the methods of determining heterotrophic carbon gain. For young leaves of T. oleifolius, heterotrophic carbon gain was around 55% on E. virosa and Acacia nebrownii. In old leaves parasitising E. virosa, heterotrophic carbon accounted for more than 80% of the total carbon. Although nitrogen content of mistletoe and host leaves was highly correlated, we could not confirm earlier findings that the difference in δ13C values of parasite-host associations depends on the nitrogen content of the host. The photosynthetic characteristics (carboxylation efficiency, photosynthetic capacity) of the parasite were only little affected by the host species being parasitised.
25
Ritter, Scott M., Chad M. Hoffman, Seth A. Ex, and Jane E. Stewart. "Impacts of lodgepole pine dwarf mistletoe (Arceuthobium americanum) infestation on stand structure and fuel load in lodgepole pine dominated forests in central Colorado." Botany 95, no. 3 (March 2017): 307–21. http://dx.doi.org/10.1139/cjb-2016-0255.
Full textAbstract:
Parasitic plants are capable of causing substantial alterations to plant communities through impacts on individual host plants. Lodgepole pine dwarf mistletoe is an important parasite in forests of the western USA that causes reductions to productivity and is thought to alter wildland fuel complexes. These impacts are hypothesized to vary with infestation severity. To test this, we used a linear mixed modeling approach to evaluate the relationship between dwarf mistletoe infestation severity and parameters representing stand structure and surface and canopy fuels in infested lodgepole pine stands in central Colorado. Infestation severity was negatively related to live basal area, average tree size, canopy base height, canopy fuel load, and canopy bulk density, and was positively related to the loading of woody surfaces fuels greater than 0.64 cm in diameter. No relationship was detected between infestation severity and live tree density, or live crown ratio. These results confirm the long-held assumption that dwarf mistletoe increases surface fuel loading in lodgepole pine communities, but also suggest that infested stands have reduced amounts of available canopy fuel. These findings have implications for potential fire behavior and highlight the importance of dwarf mistletoe in predicting the spatial and temporal dynamics of wildland fuels.
26
Gilbert, Jeannie, and David Punter. "Germination of pollen of the dwarf mistletoe Arceuthobium americanum." Canadian Journal of Botany 69, no. 3 (March 1, 1991): 685–88. http://dx.doi.org/10.1139/b91-092.
Full textAbstract:
Pollen of Arceuthobium americanum Nuttall ex Engelmann, a parasitic dwarf mistletoe of Pinus banksiana Lamb, in Manitoba, was germinated on media containing a range of concentrations of sucrose and salts. Highest germination levels occurred on 20% sucrose agar; addition of salts significantly depressed germination. Pollen germinability was below 5% at first but increased to near 50% as the season advanced. Mean germination differed significantly between flowers from 10 staminate plants but peaked at approximately the same times in association with increasing temperatures. Freezing night temperatures were followed by reduced germinability. The optimum temperature for in vitro pollen germination is close to 30 °C, whereas 40 °C impairs germination. Key words: parasitic angiosperms, microclimate, jack pine, reproductive biology.
27
Mathiasen, Robert L., and Carolyn M. Daugherty. "Comparative Susceptibility of Conifers to Western Hemlock Dwarf Mistletoe in the Cascade Mountains of Washington and Oregon." Western Journal of Applied Forestry 20, no. 2 (April 1, 2005): 94–100. http://dx.doi.org/10.1093/wjaf/20.2.94.
Full textAbstract:
Abstract A total of 24 mixed conifer stands in Washington and Oregon infested with western hemlock dwarf mistletoe (Arceuthobium tsugense subsp. tsugense) were sampled to compare host susceptibility to this parasitic plant. Temporary circular plots were established around dominant, severely infected western hemlocks (Tsuga heterophylla). Within plots, species, diameter at breast height, and dwarf mistletoe rating (6-class system) were determined for each live tree. More than 5,700 trees were sampled in 275 plots. Based on the incidence of infection, tree species were assigned to host susceptibility classes. Western hemlock is classified as the only principal host of western hemlock dwarf mistletoe. Pacific silver fir (Abies amabilis), noble fir (Abies procera), and mountain hemlock (Tsuga mertensiana) are classified as occasional hosts. Resource managers can use the host susceptibility classifications based on this study for decisions regarding which trees to retain when selectively harvesting mixed conifer stands infested with western hemlock dwarf mistletoe in the Pacific Northwest. West. J. Appl. For. 20(2):94–100.
28
Pietrzak, Wioleta, and Renata Nowak. "Impact of Harvest Conditions and Host Tree Species on Chemical Composition and Antioxidant Activity of Extracts from Viscum album L." Molecules 26, no. 12 (June 19, 2021): 3741. http://dx.doi.org/10.3390/molecules26123741.
Full textAbstract:
The content of plant secondary metabolites is not stable, and factors such as the region/location effect and seasonal variations have an impact on their chemical composition, especially in parasitic plants. Research in this area is an important step in the development of quality parameter standards of medicinal plants and their finished products. The effects of the time and place of harvest and the host tree species on the chemical composition and antioxidant activity of mistletoe extracts were investigated. Statistical tools were used to evaluate the results of the spectrophotometric and LC-ESI-MS/MS studies of the phenolic composition and antioxidant activity. The investigations indicate that the qualitative and quantitative composition, influencing the biological activity of mistletoe extracts, largely depends on the origin of the plant. The mistletoe extracts exhibited a rich phenol profile and high antioxidant activity. The chemometric analysis indicated that mistletoe collected from conifers (Viscum abietis and Viscum austriacum) had the most advantageous chemical composition and antioxidant activity. Moreover, the chemical profile and biological activity of the plant material were closely related to the climatic conditions and location of the harvested plant. Higher levels of phenolic compounds and high antioxidant activity were found in extracts obtained from plant material collected in cold weather with the presence of snow and less sunshine (autumn–winter period).
29
Pelser, Pieter B., and Julie F. Barcelona. "Discovery through photography: Amyema nickrentii, a new species of Loranthaceae from Aurora Province, Philippines." Phytotaxa 125, no. 1 (August 21, 2013): 47. http://dx.doi.org/10.11646/phytotaxa.125.1.7.
Full textAbstract:
Amyema nickrentii Barcelona & Pelser is described here as a new mistletoe species in family Loranthaceae. It was discovered through plant photography fieldwork for the Co’s Digital Flora of the Philippines website in coastal forest at Dicasalarin Cove, Baler, Aurora Province, Philippines. Amyema nickrentii differs from all other described Amyema species in having a whorled leaf arrangement with mostly nine flat linear leaves per node. This new species is named in honor of Daniel L. Nickrent, an esteemed expert on parasitic plants.
30
Ozturk, Murat, Kadir Alperen Coskuner, Yetkin Usta, Bedri Serdar, and Ertugrul Bilgili. "The effect of mistletoe (Viscum album) on branch wood and needle anatomy of Scots pine (Pinus sylvestris)." IAWA Journal 40, no. 2 (2019): 352–65. http://dx.doi.org/10.1163/22941932-40190219.
Full textAbstract:
ABSTRACTMistletoes are hemi-parasitic plants growing on many tree species. They grow on the tree branches or trunk of a tree and form root-like structures called haustoria that penetrate into the tree, taking up water and mineral nutrients. Mistletoe is capable of causing a variety of effects to its hosts, including changes in wood formation and leaf development. We investigate and discuss the effects of pine mistletoe (Viscum album ssp. austriacum, Santalaceae) on branch wood and needle anatomy of Scots pine (Pinus sylvestris, Pinaceae). Parasitized and nonparasitized branches of Scots pine were sampled from host tree crowns of trees growing on the same site. Branches were taken from mid-crown facing south. They were cut at 2 cm proximal and 2 cm distal to the mistletoe on each host branch and at the corresponding position in the case of uninfected branches from the same host. The wood anatomy at proximal and distal parts and the parts at the corresponding position in the non-parasitized section was compared. The anatomy of one-year-old needles from both parasitized and non-parasitized branches was also compared. Mistletoe had significant influences on wood and needle anatomy. The major changes were the decreases in the double wall thickness, lumen area, tangential lumen area and radial lumen area of the tracheids in the wood and a decrease in vascular area in the needles. These results help to understand how mistletoe acts on its host.
31
Hampel, Lucas D., Naowarat Cheeptham, Nancy J. Flood, and Cynthia Ross Friedman. "Plants, fungi, and freeloaders: examining temporal changes in the “taxonomic richness” of endophytic fungi in the dwarf mistletoe Arceuthobium americanum over its growing season." Botany 95, no. 3 (March 2017): 323–35. http://dx.doi.org/10.1139/cjb-2016-0240.
Full textAbstract:
Arceuthobium americanum Nutt. ex Engelm. (lodgepole pine dwarf mistletoe) is a dioecious plant parasitizing conifers in North America. Here, we documented changes in the “taxonomic richness” of culturable endophytic fungi in male and female A. americanum over the growing season. Endophytic fungi were isolated from vegetative stems of surface-sterilized aerial shoots from male and female A. americanum collected weekly from April to September. Isolated fungi were characterized macroscopically, generating a database of 48 morphologically unique forms that likely represented individual taxa. A random sample of endophytic fungi was sequenced to determine identity based on ITS rDNA. Richness increased throughout the growing season similarly in the stems of both sexes, suggesting that increased developmental age or time in the environment facilitates an increase in endophyte richness: male and female endophyte communities were 91% similar based on Sorensen’s coefficient. Sequenced endophytes came from many diverse taxa, including Serpula, Alternaria, and Tremella, which may function as mutualistic symbionts within the mistletoe. An increase in fungal richness throughout the growing season has been observed in all flowering plants examined to date, although our observation is the first for the genus and for parasitic plants in general, and has also contributed to knowledge of fungal diversity in dioecious plants.
32
Mathiasen, R., J. Melgar, J. Beatty, and C. Parks. "First Report of Psittacanthus angustifolius on Pinus oocarpa and Pinus maximinoi." Plant Disease 84, no. 2 (February 2000): 203. http://dx.doi.org/10.1094/pdis.2000.84.2.203a.
Full textAbstract:
The mistletoe Psittacanthus angustifolius Kuijt (Loranthaceae) was first described in 1987 on Pinus from Nicaragua near the Honduran border, but the species of pine was not designated (1). Kuijt (1) speculated that this mistletoe probably also occurs in Honduras. During March and October 1999 we observed P. angustifolius parasitizing Pinus oocarpa Schiede in the departments of Choluteca, Francisco Morazan, El Paraiso, Intibuca, Lempira, and Olancho in Honduras. This mistletoe appears to be a very common parasitic plant on pines in Honduras and is associated with host mortality. We also observed P. angustifolius parasitizing Pinus maximinoi H.E. Moore at two locations in the department of Lempira: one infection on a single tree 1.5 km east of El Matazano (elevation 1,400 m) and six and eight infections on two trees 0.5 km west of the main entrance to Celaque National Park east of Gracias (elevation 1,200 m). This is the first report of P. angustifolius in Honduras and the first report of this mistletoe on Pinus oocarpa and Pinus maximinoi. Specimens of P. angustifolius from Pinus oocarpa and Pinus maximinoi have been deposited at the Herbario, Escuela Nacional de Ciencias Forestales, Siguatepeque, Honduras, and at the Deaver Herbarium, Northern Arizona University, Flagstaff. Reference: (1) J. Kuijt. Ann. Mo. Bot. Gard. 74:511, 1987.
33
Monteiro, Ricardo Ferreira, Rogério Parentoni Martins, and Kikyo Yamamoto. "Host specificity and seed dispersal of Psittacanthus robustus (Loranthaceae) in south-east Brazil." Journal of Tropical Ecology 8, no. 3 (August 1992): 307–14. http://dx.doi.org/10.1017/s026646740000657x.
Full textAbstract:
ABSTRACTPsittacanthus robustus (Loranthaceae) is a Neotropical mistletoe which grows mainly on species of Vochysiaceae in Brazilian ‘cerrado’ regions. Its parasitizing pattern involves: (a) the height and the aspect of the crown of the host-plants; (b) the presence of sticky substance in the fruits of the parasite; and (c) the feeding behaviour and habitat selection of the dispersal agent, the swallowtanager Tersina viridis viridis. The feeding behaviour of this bird on fruits of P. robustus facilitates seed release and seedling establishment; its foraging habit and habitat selection account for high concentrations of the parasites on their preferred host-plants.
34
Krasylenko, Yuliya, Yevhen Sosnovsky, Natalia Atamas, Grigory Popov, Volodymyr Leonenko, Kateřina Janošíková, Nadiya Sytschak, Karol Rydlo, and Dmytro Sytnyk. "The European mistletoe (Viscum album L.): distribution, host range, biotic interactions, and management worldwide with special emphasis on Ukraine." Botany 98, no. 9 (September 2020): 499–516. http://dx.doi.org/10.1139/cjb-2020-0037.
Full textAbstract:
The hemiparasitic European mistletoe, Viscum album L. (Viscaceae), displays a rapid and remarkable expansion into natural and urban ecosystems in Ukraine. The monitoring and management of this quickly spreading species is becoming increasingly difficult as new plant species become hosts. Unlike other local mistletoe species, the European mistletoe has a broad distribution and thus requires a countrywide pest status assessment for control. This review outlines the major taxonomic and evolutionary issues pertinent to V. album with an emphasis on the characters used to distinguish its five currently recognized subspecies. The review also provides an updated distribution map and host range for the three V. album subspecies in Ukraine [V. album subsp. album, V. album subsp. abietis (Wiesb.) Janch., and V. album subsp. austriacum (Wiesb.) Vollm.], addressing the current knowledge of their biology and ecology. A significant portion of the paper is devoted to the diversity of organisms associated with V. album, including herbivores, endophytes, and parasites, drawing particular attention to major pollination and dispersal vectors, as well as potential biocontrol agents for this mistletoe species.
35
Calvin, Clyde L. "Host-Formed Tyloses in Vessels of the Mistletoe Phoradendron (Viscaceae)." IAWA Journal 18, no. 2 (1997): 117–26. http://dx.doi.org/10.1163/22941932-90001473.
Full textAbstract:
The xylem-tapping mistletoe, Phoradendron, forms vessel-to-vessel connections with its dicotyledonous host, Juglans. Contact vessels of the host may become embolized as evidenced by the presence of tyloses. Tyloses may also occur in parasite vessels contiguous with embolized host vessels. Differences between parasite and host in nuclear size, shape and intensity of staining make it possible to determine the origin of the tyloses present in contact vessels. Host-formed tyloses occluded not only emboli zed host vessels, but also those of the parasite with which they were continuous. Some parasite vessels may terminate in vessel members lacking perforations at the juncture with host vessels; these vessels lacked tyloses. In parasitic angiosperms in general tyloses within haustoria may be formed by either host or parasite. Several functional roles are reported for tyloses including; absorption of nutrients, defence against invasion of the parasite, and the occlusion of embolized vessels, as exemplified in the present study.
36
Milner, Kirsty V., Andrea Leigh, William Gladstone, and David M. Watson. "Subdividing the spectrum: quantifying host specialization in mistletoes." Botany 98, no. 9 (September 2020): 533–43. http://dx.doi.org/10.1139/cjb-2019-0207.
Full textAbstract:
Parasites necessarily depend on their hosts, but the number of host species used by a parasite varies from one to hundreds. Estimating host range and identifying the preferred host species that influence distributional boundaries and confer greater advantage to the parasite has proven elusive. As well as the confounding effects of sampling effort, characterising host specificity and preference has been hindered by considering host-use without accounting for availability. We selected three mistletoe species (Lysiana exocarpi, Amyema quandang, and Amyema lucasii) and sampled mistletoe–host interactions and host availability free from sampling bias. To quantify host specificity and identify preferred host species we applied specialist/generalist scores (G) and resource selection ratios (ω) respectively. Host specificity and preference were assessed at four scales. The generalist L. exocarpi was found to parasitise 31 plant species. Even at small scales, G values and host species turnover were high, with eight preferred hosts identified. Amyema quandang had a low G score with significant preference for half of its Acacia hosts. Amyema lucasii significantly preferred one host, consequently having low G values at all scales. By collecting potential host data and applying G scores and ω, the parasite host spectrum can be quantitatively estimated rather than qualitatively described.
37
COETZEE, J., and B. A. FINERAN. "Translocation of lysine from the host Melicope simplex to the parasitic dwarf mistletoe Korthalsella lindsayi (Viscaceae)." New Phytologist 112, no. 3 (July 1989): 377–81. http://dx.doi.org/10.1111/j.1469-8137.1989.tb00326.x.
Full text
38
Kope, H. H., S. F. Shamoun, and C. Oleskevich. "First Report of Colletotrichum gloeosporioides on Arceuthobium tsugense subsp. tsugense in Canada." Plant Disease 81, no. 9 (September 1997): 1095. http://dx.doi.org/10.1094/pdis.1997.81.9.1095b.
Full textAbstract:
Although reports of Colletotrichum gloeosporioides (Penz.) Penz. & Sacc. in Penz. occurring as a hyperparasite of western hemlock dwarf mistletoe (Arceuthobium tsugense (Rosend.) G.N. Jones subsp. tsugense) have been previously published (1), there are no collection or herbarium records to support this finding (B. Geils, personal communication). Given this ambiguity, this report is the first record of C. gloeosporioides on A. tsugense subsp. tsugense based on voucher collections deposited at the Pacific Forestry Centre (DAVFP #25277). Western hemlock dwarf mistletoe is a parasitic plant that occurs on western hemlock (Tsuga heterophylla (Raf.) Sarg.), causing growth reduction, degradation of merchantable wood, and reduction in reproductive fitness of its host. Dwarf mistletoe infections result in significant reduction in volume of mature stands of T. heterophylla in coastal British Columbia (B.C.). Aside from traditional silvicultural control methods, a potentially important control includes the use of fungi deleterious to the growth of dwarf mistletoe. C. gloeosporioides has been identified as a hyperparasite of numerous Arceuthobium spp., including A.tsugense subsp. mertensiana Hawksworth & Nickrent (1). In October 1996 and May 1997, lesions were observed on shoots of A. tsugense subsp. tsugense collected from two field sites, Cowichan Lake (48°56′N, 124°23′W) and Duncan (48°45′N, 123°50′W), B.C. Acervuli containing masses of spores and dark setae were observed within lesions, and conidia from the acervuli produced pure cultures of C. gloeosporioides. The fungus was identified based on conidial and cultural characteristics (2). Conidia were cylindrical to elliptical in shape and measured 12.5 to 15.0 × 2.5 to 4.0 μm. On potato dextrose agar, colonies developed a white to patchy, dark gray mycelial mat with conidia produced in mycelia and in distinct salmon-colored masses. Colony growth occurred at 10 to 30°C, with optimum growth at 20°C, while maximum germination was observed at 30°C after 24 h, with germination occurring between 10 and 35°C. Branches with healthy mistletoe shoots were cut from western hemlock trees and placed in Hoagland's nutrient solution. A spore suspension (106 conidia per ml) was brushed onto mistletoe shoots at a rate of approximately 1 ml per replicate, with 8 to 10 replicate branches, each containing a cluster of >5 shoots. Controls were treated with sterile, distilled water and branches were incubated in the greenhouse with 55% relative humidity. The fungus was re-isolated from acervuli that developed on inoculated shoots after 14 days, and these results were repeated in a second experiment. The fungus was not isolated from the controls. Koch's postulates were fulfilled by inoculating shoots of A. tsugense subsp. tsugense and re-isolating the pathogen from symptomatic stems. C. gloeosporioides could be an important control measure for western hemlock dwarf mistletoe. References: (1) F. G. Hawksworth and D. Weins. 1996. Agric. Handb. 709, USDA, Forest Service, Washington, D.C. (2) B. C. Sutton. 1980. The Coelomycetes. Commonw. Mycol. Inst., Kew, England.
39
Anjani, Malia, Nour Athiroh AS, and Nurul Jadid Mubarakati. "Studi Subkronik.28 Hari: Uji Toksisitas Ekstrak Metanolik Kombinasi Scurulla atropurpurea dan Dendrophthoe pentandra terhadap Kerusakan Fungsi Ginjal Tikus Wistar Betina." BIOSAINTROPIS (BIOSCIENCE-TROPIC) 6, no. 2 (January 25, 2021): 58–63. http://dx.doi.org/10.33474/e-jbst.v6i2.322.
Full textAbstract:
Mistletoe tea (Scurrula. atropurpurea (Bl.) Dans) and Mistletoe Mango (Dendrophthoe pentandra) are parasitic plants that live on tea and mango plants, very potential as medicines, containing several secondary metabolite compounds such as flavonoids (quercetin). Flavonoids can act as natural antioxidants that can protect the kidneys from free radicals. Damage to kidney function can indicate from creatinine, BUN, urea, and renal histopathology. The.purpose.of.this study was.to determine toxicity of. a combination of. Mistletoe tea. extract and mango mistletoe (EMBTBM) to damage kidney function in female Wistar rats for 28 days, using the true experimental design method. Data on creatinine, bun, urea, and renal histopathology data were analyzed using the ANOVA. test. The number of test animals is 20 female white rats divided into four groups; each group there are five rats. Group.1 a control, then groups 3, and 4. as. treatment. Based on the results of the study showed that statistically significant. between. all groups. was p> 0.05. Therefore,.EMBTBM given to female.rats for.28 days at a dose.of 250 mg/KgBB, 500.mg/KgBB, and.1000 mg/KgBB reduces levels of creatinine, bun, urea and renal cell necrosis, in this case, the administration of EMBTBM tends to be safe and does not cause rise toxic properties in damage to kidney function in female Wistar rats.
Keywords: .Subchronic, kidney function, and extract.
ABSTRAK
Benalu teh (Scurrula atropurpurea (Bl.) Dans) dan Benalu Mangga (Dendrophthoe pentandra) merupakan tanaman parasit yang hidup.menumpang pada tanaman teh dan mangga, sangat berpotensi sebagai obat-obatan, karena mengandung senyawa flavonoid yaitu quercetin dan rutin. Flavonoid berperan sebagai penyedia. antioksidan. alami. yang. melindungi. ginjal dari zat radikal.bebas. Kerusakan.fungsi ginjal diindikasi dari. kadar. kreatinin, BUN, urea, dan histopataologi ginjal. Tujuan penelitian ini adalah mengetahui. toksisitas pemberian. kombinasi ekstrak. benalu. teh. dan benalu mangga (EMBTBM) terhadap kerusakan fungsi ginjal pada tikus wistar betina selama 28 hari, dengan metode true eksperimental design. Data kadar kreatinin, bun, urea, dan histopatologi ginjal dianalisis menggunakan uji ANOVA. Penelitian ini menggunakan hewan.coba.berjumlah. 20. ekor. tikus. putih. betina. Hewan coba dibagi. menjadi 4.kelompok denga 5 ekor tikus pada tiap kelompok. Kelompok.1sebagai. kontrol, sementara kelompok. 3 dan 4 diberi perlakuan EMBTBM. Hasil. penelitian. menunjukan bahwa. perbedaan. nilai signifikan. antara. semua. kelompok. yaitu p>0.05..EMBTBM yang disondekan pada tikus wistar betina.selama 28.hari. dengan. dosis yang diberikan yaitu 250. mg/KgBB, 500. mg/KgB, dan 1000. mg/KgBB menurunkan kadar kreatinin, bun, urea dan nekrosis sel ginjal, dalam hal ini pemberian EMBTBM cenderung aman dan tidak menimbulkan sifat toksik pada kerusakan fungsi ginjal tikus wistar betina.
Kata Kunci. : Ekstrak, Fungsi ginjal, dan Subkronik.
40
Omeje, Edwin Ogechukwu, Patience Ogoamaka Osadebe, Charles Okechukwu Esimone, Chukwuemeka Sylvester Nworu, Akira Kawamura, and Peter Proksch. "Three hydroxylated lupeol-based triterpenoid esters isolated from the Eastern Nigeria mistletoe parasitic onKola acuminata." Natural Product Research 26, no. 19 (October 2012): 1775–81. http://dx.doi.org/10.1080/14786419.2011.603316.
Full text
41
Munro, Kaitlyn C., Jeffrey R. M. Jackson, Ivan Hartling, Michael J. Sumner, and Cynthia M. Ross Friedman. "Anther and pollen development in the lodgepole pine dwarf mistletoe (Arceuthobium americanum) staminate flower." Botany 92, no. 3 (March 2014): 203–14. http://dx.doi.org/10.1139/cjb-2013-0276.
Full textAbstract:
The lodgepole pine dwarf mistletoe, Arceuthobium americanum Nutt. ex Engelm., is a parasitic angiosperm that infects conifers in western Canadian forests. While production of viable pollen in anthers is critical to dwarf mistletoe reproduction, the few existing reports that examine staminate development in Arceuthobium are often incomplete or conflicting. The objective of this work was to investigate the developmental anatomy of anther and pollen of A. americanum using modern microscopy. We found that the microsporangium was toroidal from the outset and gave rise to a central peg-shaped sterile “columella” early in anther development. The endothecium was absent, the epidermis persisted as an “exothecium” fulfilling the role of the endothecium, and a primary parietal layer generated a secretory tapetum and middle layer. Thus, we suggest that a new category of anther wall development, the Arceuthobium type, be created. Microsporogenesis produced tetrahedral microspores via simultaneous cytokinesis and involved callose wall formation. Microgametogenesis resulted in round and atypical generative and vegetative nuclei. Additionally, the heterocolpate, echinate pollen grains, which were shed at the two-celled stage, were seen for the first time in their native state with environmental scanning electron microscopy. This work contributes to the understanding of A. americanum, the genus Arceuthobium, and angiosperms as a whole.
42
Schneider, Adam C., Kate M. Sanders, Jacob H. Idec, Yun Jee Lee, Shawn C. Kenaley, and Robert L. Mathiasen. "Plastome and Nuclear Phylogenies of Dwarf Mistletoes (Arceuthobium: Viscaceae)." Systematic Botany 46, no. 2 (August 11, 2021): 389–402. http://dx.doi.org/10.1600/036364421x16231782047307.
Full textAbstract:
Abstract— Dwarf mistletoes are a lineage of morphologically-reduced stem parasites inhabiting Pinaceae and Cupressaceae throughout the northern hemisphere and equatorial East Africa. Though diagnosable by a suite of morphological traits, phylogenetic knowledge of species relationships has been limited to studies employing either comprehensive taxonomic sampling of one or two genes, or more sequence data from a limited number of individuals. We used data from genome skimming to assemble 3kb of the nuclear ribosomal cistron and up to 45kb of the plastome to clarify the phylogenetic root of the genus, monophyly of species, and relationships among infraspecific taxa. Genomic differentiation among terminal taxa was variable; however, we found strong support for reciprocally monophyletic New World and Old World lineages, congruent nrDNA and plastome topologies at the species level and below, and monophyly of most taxonomic sections and species. Plastome gene content was stable across the genus with minimal pseudogenization or loss, as in other hemiparasites, with the notable exception of cemA. These findings form the basis of our re-evaluation of historical biogeographical hypotheses, species- and subspecies-level taxonomy, and plastome evolution in Arceuthobium. More broadly, this work provides a foundation for future clade-focused comparative and biosystematics studies of Arceuthobium.
43
Silva, Mateus Cardoso, Aretha Franklin Guimarães, Grazielle Sales Teodoro, Sara Souza Bastos, Evaristo Mauro de Castro, and Eduardo van den Berg. "The enemy within: the effects of mistletoe parasitism on infected and uninfected host branches." Plant Ecology 222, no. 5 (April 6, 2021): 639–45. http://dx.doi.org/10.1007/s11258-021-01132-6.
Full text
44
Sanogo, Soum, and Phillip Lujan. "Rarity of a Fungal Pathogen and a Parasitic Flowering Plant Versus the Commonness of a Mycorrhizal Fungus in Pecan Orchards in New Mexico." Plant Health Progress 19, no. 3 (January 1, 2018): 207–11. http://dx.doi.org/10.1094/php-05-18-0024-s.
Full textAbstract:
This study documents the occurrence of the fungal pathogen Inonotus rickii, which causes wood rot or heart rot; the leafy mistletoe Phoradendron tomentosum (subsp. macrophyllum); and the mycorrhizal fungus Pisolithus tinctorius in pecan orchards in southern New Mexico. The prevalence of orchards with I. rickii and P. tomentosum was low (3.3 to 3.6%). To our knowledge, I. rickii has not been previously described in association with pecan in New Mexico and the United States. Although the occurrence of P. tomentosum on pecan has been documented in the southeastern United States, it has not been reported in New Mexico. In contrast to the rarity of I. rickii and P. tomentosum, the mycorrhiza P. tinctorius was commonly found in pecan orchards surveyed. With the expansion of the pecan industry in New Mexico, it is important to continually monitor pecan orchards for emerging pests and pathogens that may impose an economic threat to production and to enhance the proliferation of biological entities with known beneficial properties for pecan health.
45
Kotan, Recep, Akif Okutucu, Arzu Ala Görmez, Kenan Karagoz, Fatih Dadasoglu, İsa Karaman, İsmet Hasanekoglu, and Şaban Kordali. "Parasitic Bacteria and Fungi on Common Mistletoe (Viscum album L.) and Their Potential Application in Biocontrol." Journal of Phytopathology 161, no. 3 (November 16, 2012): 165–71. http://dx.doi.org/10.1111/jph.12048.
Full text
46
Rey, L., A. Sadik, A. Fer, and S. Renaudin. "Étude de quelques aspects du métabolisme carboné et azoté chez l'Arceuthobium oxycedri, gui nain du genévrier." Canadian Journal of Botany 70, no. 8 (August 1, 1992): 1709–16. http://dx.doi.org/10.1139/b92-211.
Full textAbstract:
In juniper dwarf mistletoe, Arceuthobium oxycedri (DC) M. Bieb., a hemiparasitic and epiphytic Angiosperm characterized by very reduced and slow development, the chlorophyll content of the shoots is relatively high for a parasitic plant. However, gas exchanges reveal a low net gain in carbon, and the real photosynthetic intensity is only about 1.5 to 2 times higher than the respiratory intensity in these organs. In the endophytic system, which is also chlorophyllous, a small amount of photosynthetic activity also occurs. By studying 14CO2 assimilation and carboxylase activities in both organs, it was possible to determine the ability of the parasite to satisfy part of its carbon requirements. Following the administration of 14CO2, radioactivity was mainly recovered in carbohydrates and to a lesser extent in organic acids and amino acids. This demonstrates that A. oxycedri has some autonomy for the fixation and distribution of carbon into various compounds. On the other hand, the parasite, since it is epiphytic, is completely dependent upon its host for nitrogen. The study of the activities of the key enzymes of nitrogen metabolism ([Formula: see text] and [Formula: see text] reductases, glutamine synthetase, glutamate dehydrogenase, glutamate-oxalacetate transaminase) shows that nitrogen supply from the host certainly occurs mainly in the form of reduced nitrogenous compounds (ammonia and (or) aminated organic compounds). The numerous labelled amino acids recovered after administration of 14CO2 show that A. oxycedri is able to redistribute the imported nitrogen in various ways. Key words: Arceuthobium oxycedri, parasitic Angiosperms, carbon nutrition, nitrogen nutrition.
47
Solikin, Solikin. "Infestation of mistletoe Dendrophthoe pentandra (L.)Miq on various canopy shading and plants diversity in Purwodadi Botanic Garden: A study on medicinal plant Cassia fistula L." Berkala Penelitian Hayati 26, no. 1 (October 19, 2020): 1–7. http://dx.doi.org/10.23869/bphjbr.26.1.20201.
Full textAbstract:
Mistletoe Dendrophthoe pentandra (L.)Miq is a parasitic plant commonly found parasitizing and infesting medicinal plants such as Cassia fistula L. This research aimed to investigate the infestation of D. pentandra on C. fistula on various trees canopy shading, infested host number and plant diversity. Study was conducted in Purwodadi Botanic Garden which located in Purwodadi, Pasuruan, East-Java during January-March 2020. Data Collection was conducted by explorative and descriptive methods in each block locations in the garden. Sampling plots were determined by purposive sampling method using 20x20 m per plot in each block where the tree of C. fistula found. The canopy shading was categorized as : open (4) = light interception more than 90%, rather open (3) = light interception = 60-90%, rather shady (2) = light interception 30-60%, shady (1) (light interception less than 30%). The result showed that the infestation of D. pentandra was affected significanly by the plant canopy shading and the infested host number in the blocks. The highest infestation of misletoe D. pentandra on C. fistula was found in the open canopy and the highest infested host plants in the block III.D with the parasite number 13 per plant. The tree plant diversity in the blocks tend to have negative correlation to the infestation of D. pentandra on C. fistula with r = -0.18.
48
TENNAKOON, K. U., and J. S. PATE. "Effects of parasitism by a mistletoe on the structure and functioning of branches of its host." Plant, Cell and Environment 19, no. 5 (May 1996): 517–28. http://dx.doi.org/10.1111/j.1365-3040.1996.tb00385.x.
Full text
49
Teixeira-Costa, Luíza, and Gregório Ceccantini. "EMBOLISM INCREASE AND ANATOMICAL MODIFICATIONS CAUSED BY A PARASITIC PLANT: PHORADENDRON CRASSIFOLIUM (SANTALACEAE) ON TAPIRIRA GUIANENSIS (ANACARDIACEAE)." IAWA Journal 36, no. 2 (May 20, 2015): 138–51. http://dx.doi.org/10.1163/22941932-00000091.
Full textAbstract:
Parasitic plants are capable of causing a variety of effects to their hosts, including alterations in the process of wood formation. However, the majority of studies dealing with parasitic plant anatomy have focused on the host–parasite interface and the direct action of the haustorium, which is the organ responsible for attaching the parasite to the host. Considering this gap, we studied the anatomical and functional effects caused by a mistletoe species, Phoradendron crassifolium (Santalaceae), on the wood anatomy of the host tree Tapirira guianensis (Anacardiaceae). Both parasitized and non-parasitized branches were collected from host trees. Traditional wood anatomy procedures were employed, along with functionality experiments using the ascent of safranin solution through the xylem. Prior to the analysis, all sampled branches were divided in “upstream” and “downstream” portions, considering the direction of xylem sap flow inside the plant body. This design was chosen in order to avoid biased results derived from normal ontogeny-related wood anatomical and functional changes. Our results showed that infested wood expressed a higher density of embolized vessels, narrower vessel lumen diameter, higher vessel density, taller and wider rays, and fibers with thinner cell walls. All these responses were most conspicuous in the downstream sections of the parasitized branches. We propose that the wood anatomical and functional alterations were induced by the combination of water stress caused by water use by the parasite and consequent low turgor in differentiating cambial derivates; by unbalanced auxin/cytokinin concentrations originating at the infestation region due to phloem disruptions caused by the parasite’s penetration and action; and by higher than usual ethylene levels. Further analysis of hydraulic conductivity and hormonal changes in host branches are necessary to test this hypothesis.
50
Ross, Cynthia M., and Michael J. Sumner. "Ultrastructure of the fertilized embryo sac in the dwarf mistletoe Arceuthobium americanum (Viscaceae) and development of the caecum." Canadian Journal of Botany 83, no. 5 (May 1, 2005): 459–66. http://dx.doi.org/10.1139/b05-024.
Full textAbstract:
Post-fertilization changes in the seven-celled embryo sac of the parasitic angiosperm Arceuthobium americanum Nutt. ex Engelm. were investigated with light, fluorescence, and electron microscopy. Two embryo sacs, of which only one is fertilized, are found within the reduced ategmic ovule (the placentalnucellar complex). All cells of the fertilized embryo sac developed thickened cellulosic and (or) hemicellulosic bounding walls and, aside from the degenerative synergid, acquired ultrastructure reflective of metabolically active cells. The filiform apparatus became thickened in the persistent synergid, and a similar structure developed in the antipodals. Unlike the changes observed in the zygote and central cell, those in the persistent synergid and antipodals were unusual, as these cells regularly degenerate after fertilization in a typical angiosperm; therefore, in A. americanum, they likely play a role in providing nutrition to the zygote and (or) central cell. A pouch-like outgrowth (caecum) initiated from the central cell near the primary endosperm nucleus and, after vacuolar expansion and intercellular growth, reached the base of the placentalnucellar complex in three days. The observation of mitochondria clusters within the central cell, caecum, and adjacent placentalnucellar complex cells suggests the caecum functions in embryo sac expansion and haustorial nutrient absorption.Key words: Arceuthobium, caecum, cell walls, fertilized embryo sac, mistletoe, ultrastructure.