Scientific Name
Deschampsia elongata (Hook.) Munro (Synonyms: Aira elongata)
Common Name(s)
Slender hairgrass
Tribe / Family Name
Poeae
Flowering Period
June to August
Symbol
DEEL
Description
Slender hairgrass is a native cool-season perennial bunchgrass that reproduces from seeds and tillers. Culms usually range from 30–120 cm in height. Its inflorescence is a contracted panicle usually 5–30 cm long with long ascending branches pressed against the main stem and erect to nodding. Spikelets are 3–6.7 mm long, narrowly V-shaped, pale greenish to purplish, 2(3)-flowered, and awned (the lemma awns are usually up to 5 mm long, straight to slightly geniculate, and attached below the middle of the lemmas). Ligules are sometimes up to 8 mm long, membranous, acute to acuminate, entire, glabrous, and decurrent.
General Info
This short-lived species can be found in wet habitats, such as mountain meadows; margins of streams, ponds, and lakes; disturbed areas such as roads and trails; and in montane and alpine sites.
Similar Species
Slender hairgrass may look similar to other hairgrass (Deschampsia) species, such as tufted hairgrass (Deschampsia cespitosa) and annual hairgrass (Deschampsia danthonioides). To differentiate these species from each other, compare their heights, size of the lemma awns, and inflorescences. Although slender hairgrass and tufted hairgrass are taller plants with lemma awns usually up to 5 mm long, they can be separated by examining their inflorescences: slender hairgrass has a contracted panicle inflorescence, while tufted hairgrass has a shiny, often nodding, contracted to open, diffuse panicle inflorescence. Annual hairgrass has lemma awns usually up to 7.5 mm long and is a smaller plant with panicle inflorescences that are much broader and open than slender hairgrass. Slender hairgrass may also look similar to dense silkybent (Apera interrupta).
Picture of growth habit.
Close-up picture of contracted panicle inflorescences.
Close-up picture of spikelet.
Close-up picture of membranous ligule.
Illustration of slender hairgrass. USDA-NRCS PLANTS Database / Hitchcock, A.S. (rev. A. Chase). 1950. <i>Manual of the grasses of the United States</i>. USDA Miscellaneous Publication No. 200. Washington, DC.