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GRASSES
OF THE COLUMBIA BASIN OF BRITISH COLUMBIA
The genus is named after the French botanist Jean Deslongchamps (1774-1849). The species in this genus are all perennial except for the annual Deschampsia danthonoides. Deschampsia species were once included in Aira, but that genus is now agreed upon to include only delicate annuals of which there are two species in North America. Cody (1996) separates the two genera on characters such as whether the length of the glume is shorter than the spikelet (as in Deschampsia) or is equal to or exceeds the uppermost flower (as in Aira).
Leaves and Stem: The open sheaths range from smooth to rough to the touch. The ligules are 4-8 mm long, hairy, pointed to blunt and often split. The leaves are matted at the base and often stiff. The leaf blades are flat or rolled inward and 1.5-4 mm wide. The leaf veins are raised. There are no auricles. Flowerhead and Flowers: The loose, open flowerhead is 8-25 cm long and has branches that spread or droop or may be pressed close to the stem axis. The flowerhead appears shiny and can have purplish to tawny coloured spikelets. The nearly equal glumes are narrow and longer than the flowers. The lemmas are ragged along the upper tip, 2.5-5 mm long and have callus hairs at the base that are 1 mm long. The 2.5-4-mm-long awn is attached near the base of the lemma. Similar Species: The features of Tufted Hairgrass vary considerably and some authors have described several varieties. Douglas et al. (1994) have described two subspecies: beringensis and cespitosa. Subspecies beringensis occurs in saline meadows and tidal marshes. Subspecies cespitosa occurs east of the Coast-Cascade mountains in the montane to alpine zones. The glumes of ssp. cespitosa are less than 5 mm long, and the branches of the flowerhead are pressed toward the stem axis at maturity. Subspecies beringensis has longer glumes and an open (spreading branches) flowerhead at maturity.
Leaves and Stem: One to several stems arise from a few leaves at the base. Sheaths are open. The leaf blades are 1-1.5 mm wide, usually inrolled and concentrated at the base. The ligules are 3-6 mm long and somewhat pointed. There are no auricles. Flowerhead and Flowers: The flowerhead varies from narrow to spreading, and is up to 25 cm long. Spikelets are generally two-flowered. The two nearly equal, relatively long glumes are longer than the upper flower. Lemmas are firm, smooth, shining, purplish and about 2.5 mm long. A bent awn extends from the middle of the back of the lemma. Similar Species: Its annual growth habit distinguishes Annual Hairgrass from other species.
Leaves and Stems: The open sheaths are smooth and auricles are absent. The ligules are 3-9 mm long, pointed and have a smooth edge, unless torn during the emergence of the flowerhead. The leaves usually occur as a basal tuft and the basal leaves are hairlike. Leaves along the stem are flat or inrolled, but rarely over 1.5 mm wide. Flowerhead and Flowers: The narrow flowerhead has slender upward pointing branches, and is pale-green to purple. The nearly equal, pointed glumes are equal to or exceed the upper flower in length. The blunt-tipped lemmas are firm, smooth and shining. The blunt upper tip has a ragged edge. The lemma awn is attached just below the mid-point and is 3-4 mm long and nearly straight. The bearded callus has hairs that are half as long as the lemma. Similar Species: Slender Hairgrass resembles Tufted Hairgrass, but Slender Hairgrass has fine, hairlike leaves rather than flat leaves.
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