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''Cuscuta'' () (dodder) is a genus of about 100–170 species of yellow, orange, or red (rarely green) parasitic plants. Formerly treated as the only genus in the family Cuscutaceae, it now is accepted as belonging in the morning glory family, Convolvulaceae, on the basis of the work of the Angiosperm Phylogeny Group.〔Stefanovic', S. and R. G. Olmstead. (2004). Testing the phylogenetic position of a parasitic plant (''Cuscuta'', Convolvulaceae, Asteridae): Bayesian inference and the parametric bootstrap on data drawn from three genomes. ''Syst Biol'' 53(3): 384–399. doi:10.1080/10635150490445896〕 The genus is found throughout the temperate and tropical regions of the world, with the greatest species diversity in subtropical and tropical regions; the genus becomes rare in cool temperate climates, with only four species native to northern Europe.〔Costea, M. 2007-onwards. (Digital Atlas of ''Cuscuta'' (Convolvulaceae). ) Wilfrid Laurier University Herbarium, Ontario, Canada.〕 Folk names include wizards net, devil's guts, devil's hair, devil's ringlet, goldthread, hailweed, hairweed, hellbine, love vine, pull-down, strangleweed, angel hair, and witch's hair.〔 ==Appearance== Dodder can be identified by its thin stems appearing leafless, with the leaves reduced to minute scales. In these respects it closely resembles the similarly parasitic, but unrelated genus ''Cassytha''. From mid-summer to early autumn, the vines can produce small fruit that take the same color as the vine, and are approximately the size of a common pea. It has very low levels of chlorophyll; some species such as ''Cuscuta reflexa'' can photosynthesize slightly, while others such as ''C. europaea'' are entirely dependent on the host plants for nutrition.〔Machado, M. A. & K. Zetsche. (1990). A structural, functional and molecular analysis of plastids of the holoparasites ''Cuscuta reflexa'' and ''Cuscuta europaea''. ''Planta'' 181: 91–96.〕 Dodder flowers range in color from white to pink to yellow to cream. Some flower in the early summer, others later, depending on the species. The seeds are minute and produced in large quantities. They have a hard coating, and typically can survive in the soil for 5–10 years, sometimes longer. Dodder seeds sprout at or near the surface of the soil. Although dodder germination can occur without a host, it has to reach a green plant quickly and is adapted to grow towards the nearby plants by following chemosensory clues. If a plant is not reached within 5 to 10 days of germination, the dodder seedling will die. Before a host plant is reached, the dodder, as other plants, relies on food reserves in the embryo; the cotyledons, though present, are vestigial.〔Macpherson, G. E. (1921). Comparison of development in dodder and morning glory. ''Botanical Gazette'' 71: 392–398.〕 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「cuscuta」の詳細全文を読む スポンサード リンク
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