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GRASSES OF THE COLUMBIA BASIN OF BRITISH COLUMBIA Heather Stewart, Richard Hebda Major Groups of Grasses Table of Contents Glossary Oryzopsis Rough-leaved Ricegrass In this paper, we treat Oryzopsis as a monotypic genus endemic to North America, consisting only of Oryzopsis asperifolia. Barkworth (1998) has placed the remaining species in Piptatherum. The name Oryzposis comes from the Greek oryza, meaning rice, and opsis, meaning appearance in reference to its resemblance to rice. Oryzopsis is separated from Piptatherum on the basis of the overwintering basal leaves that remain green, the reduced stem leaves (<1 cm long) and a dense ring of callus hairs. Piptatherum has basal leaves that die in winter, stem leaves that are longer than 1 cm and callus hairs that are scattered if present. Oryzopsis also resembles Stipa, but has a shorter callus and awns. Oryzopsis is nutritious and palatable, but not generally a grass that is important as forage.   Oryzopsis asperifolia Michx. Rough-leaved Ricegrass Plant: Oryzopsis asperifolia is a native species that grows to 20-50 cm tall. It is a loosely tufted perennial with a flowerhead that is reduced to a simple one-sided spike. Leaves and Stem: Sheaths are open to the base and there are no auricles. Blunt, membranelike ligules are 0.5 mm high and have a margin of tiny hairs. The basal leaves are 4-10 mm wide, flat or inrolled, lax and are rough to the touch. They remain green overwinter. The stem leaves are less than 1 cm long. Flowerhead and Flowers: The flowerhead spikelets are 5-12 cm long and crowded into a spike. The flowerhead appears as if the spikelets are arranged on one side of the stem. There is only one flower in each spikelet. The glumes are smooth and extend into a short hair at the tip. The first glume is slightly shorter than the second. The hardened lemma equals the glume and has short, whitish hairs scattered on its surface. The edges of the lemma overlap at maturity and the palea is hidden. The lemma extends into a 7-10-mm-long awn. Habitat: Rough-leaved Ricegrass is a native species that grows on dry, gravelly soil such as talus slopes, or in mixed woods in moist depressions. Rough-leaved Ricegrass grows in solitary, bright green tufts that are scattered throughout the site in all seasons (Berg, 1999, pers.comm.). In the Columbia Basin region it occurs in Yoho National Park, along the Kootenay River and at Valemont. Similar Species: The short-stem leaves of Rough-leaved Ricegrass, as well as the evergreen basal leaves, differentiate it from other species.

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