Distribution, habitat and status for perennial Triticeae species in Japan
von Bothmer, Roland; Salomon, Björn Enomoto; Watanabe, Osamu
published: Dec 14, 2005
A detailed study of the current Japanese distributions of the Triticeae species is presented together with data on general distribution outside of Japan. Data on habitat preferences, chromosome numbers, relationships and the current status for each species is given. In Japan, 13 species of perennial Triticeae occur belonging to the three genera Elymus, Leymus, and Hystrix. Quackgrass, E. repens, was probably introduced as a weed and H. komarovii is possibly introduced too, whereas all other species are thought to be native to the country. Three species are endemic in the country, viz., E. yubaridakensis, with the single location on Mt. Yubari in Hokkaido, E. humidus, a specialized weed in rice paddies with a markedly decreasing distribution in later years due to habitat destruction, and H. japonica, a species of moist montane forests in southern Japan. Some species with wider distributions on the Asiatic mainland are very rare in Japan, such as H. komarovii, with only a single location on northern Hokkaido and E. gmelinii and E. sibiricus, both occurring at higher altitudes on Honshu. Two species with preferences for a warm temperate area are very common in Japan, namely E. ciliaris and E. tsukushiensis.