out-crossing. The first seeds become viable 5 to 9 days after flowering and all are viable after 20 days. Seeds are shed from in summer and early autumn. One panicle has 100 to 380 seeds, with 177,000 to 240,000 seeds per plant, depending on time of emergence. Invasive species In North America, Holcus lanatus is an invasive species in native grasslands and other ecosystems. In Yosemite National Park it is one of nine priority noxious weeds to control for habitat restoration and regenerating native plant balances. It forms dense stands that can exclude other plants. It is also established in Chile and Australia. Ecology Holcus lanatus in its natural habitat is a food source for butterflies such as the speckled wood, the wall, and especially the small skipper. It is rarely utilized by the Essex skipper. In its native range it may occur in plant associations such as the Juncus subnodulosus–Cirsium palustre fen-meadow habitat. See also Invasive grasses of North America Notes References Lamp, Forbes and Cade. Grasses of Temperate Australia. Bloomings Books. 1990. Pooideae Flora of Africa Flora of Asia Flora of Europe Plants described in 1753 Taxa named by Carl Linnaeus