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''Phoradendron tomentosum'', the leafy mistletoe, hairy mistletoe or Christmas mistletoe, is a plant parasite. It is characterized by its larger leaves and smaller berries than dwarf mistletoe. Leafy mistletoe seldom kill but they do rob their hosts of moisture and some minerals, causing stress during drought and reducing crop productions on fruit and nut trees.〔Krautwurst, Terry. “ The truth About Mistletoe.” Mother Earth News, 195 (2003): 26-29〕 Leafy mistletoe has the ability to photosynthesize on its own but it relies on other plants in order to obtain its nutrients. It attaches itself to a tree and then grows haustoria,〔Hiller, Julie Brooks. “Marvelling at Mistletoe.” Highlights for Children. 65, no 12:40-41〕 in order to get the food and water it needs. ==Host and Symptoms== Symptoms can include dieback, swelling, formations of witches’ broom and weakened branches. Leafy mistletoe can occur on several hundred host species. 〔 These include hardwood trees. Signs are green leafy green stems, and berries. ==Disease Cycle== Birds are the primary disease vector in the dispersal of the plant parasite leafy mistletoe.〔Aukema, J. E. 2004. Distribution and Dispersal of Desert Mistletoe is Scale-Dependent, Hierarchically Nested. Ecography 27. pp. 137-144.〕 Birds consume the seeds from the fruit of ''P. tomentosum,'' also called drupes, and excrete or regurgitate the seeds onto the branches of which the birds perch. The most important birds for effective dispersal include cedar waxwings, euphonias, silky flycatcher, bluebirds, thrushes, robins, and solitaires.〔Geils, B.W., Wiens, D., Hawksworth, F. G. Phoradendron in Mexico and the United States. USDA Forest Service Gen Tech. Rep. 2002〕 The seeds germinate within the tree for several years, eventually producing a haustorium, a root-like structure, that penetrates the host plant and extracts water and minerals from the infected tree or plant. Phoradendron is a hemiparasite, meaning that it produces its own chlorophyll, but relies on the host plant to provide essential elements for growth and survival. 〔W T Watson, T Martinez-Trinidad. Strategies and treatments for leafy mistletoe (Phoradendron tomentosum (DC.) Engelm ex. Gray) suppression on cedar elm (Ulmus crassifolia Nutt.) Arboriculture and Urban Forestry (2006) Volume: 32, Issue: 6, Pages: 265-270〕 Stems, flowers, and fruits also grow from the seed following germination with fruits being produced several years after infection.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Phoradendron tomentosum」の詳細全文を読む スポンサード リンク
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