Danthonia compressa flattened oatgrass Poaceae DACO; Bx, pb; NY, ct; R, cl, gb;

 

Danthonia compressa inflorescence. By Arthur Haines. Copyright © 2018. New England Wild Flower Society. gobotany.newenglandwild.org

Danthonia compressa inflorescence. By Arthur Haines. Copyright © 2018. New England Wild Flower Society. gobotany.newenglandwild.org (Accessed 2/2018).

Danthonia compressa stem and ligule. Copyright� 2006 John R. Gwaltney. Southeastern Flora. southeasternflora.net

Danthonia compressa stem and ligule. Copyright� 2006 John R. Gwaltney. Southeastern Flora. southeasternflora.net (Accessed 2/2018).

Danthonia compressa is a perennial (probably a C3 grass see Waller and Lewis 1979) , fine, tufted; stems slender, some nodes flattened, 40-80 cm, sheaths glabrous. 

Leaves with blades to 20 cm long, 0.2-0.4 cm wide (about half the length of the flowering stem). 

Danthonia compressa open spikelet. R. W. Smith. University of Michigan Herbarium. mchiganflora.net

Danthonia compressa open spikelets. R. W. Smith. University of Michigan Herbarium. mchiganflora.net (Accessed 2/2018).

Flower spikelets 2-3 per branch, glumes 0.9-1.3 cm, lemmas with long, usually twisted awn arising between whisker-like teeth, 0.2-0.4 cm long at apex, several florets; inflorescence sparse, lax, 5-10 cm, branches, stalks of lower branches longer than the spikelets, often bent back when blooming; June-Aug. 

Wetland status: FACU. 

Frequency in NYC: Infrequent. 

Origin: Native. 

Habitat: Moist to dry open woods, tolerant of shade, fire, intolerant of salt, soil pH 4.8-7 (USDA, NRCS 2010). Less tolerant of drought and poor soil than D. spicata (see below).

Notes: Often infected with an endophytic fungus, Atkinsonella hypoxylon (Clavicipitaceae, Ascomycetes), (Clay and Leuchtmann 1989).