Status and Distribution of Illinois Populations of Stenanthium gramineum (Ker-Gawl.) Morong, Grass-Leaved Lily (Liliaceae): an Endangered Plant in Illinois

Stenanthium gramineum (Ker-Gawl.) Morong (grass-leaved lily) is known historically from 19 populations in 13 counties in Illinois. Seven populations in the southern one-third of the state are extant and three extirpated; nine could not be located. Population size ranged from 106 plants at the Richand County site to 611 at a Pope County site. All of the populations occupied an area of 75 m² or less. Flower production was not observed at any of the sites in 2002. The populations occurred on acid soils in a floodplain forest, in upland forests with north- and east-facing slopes, and a gravel wash of an intermittent stream.