Arrhenatherum elatius

Tall oat grass

Family: Poaceae · Type: perennial · Not Native

Tall oat grass is a naturalized perennial grass found in northwestern California, the Cascade Range, northern and central Sierra Nevada Foothills, central Sierra Nevada, Central Coast, San Francisco Bay Area, Western Transverse Ranges, and Modoc Plateau in disturbed, open sites at elevations of 30 to 1,800 meters. Flowering from May to July, this grass produces pale, translucent spikelets with soft-hairy keels in loose clusters 7 to 30 centimeters long. Growing with ascending to erect stems 50 to 180 centimeters tall, it forms dense tufts and sometimes develops rhizomes with distinctively bulbous basal internodes. Its leaves are flat, 5 to 30 centimeters long and 3 to 8 millimeters wide, with obtuse ligules that are minutely ciliate and glabrous to slightly rough blades. The distinctive lower lemma features an awn 10 to 17 millimeters long, creating a characteristic wispy appearance in disturbed grassland areas.

Habitat: Disturbed, open sites

Bloom period: May-Jul

Elevation: 30-1800 m

Bioregions: NW, CaR, n&ampc SNF, c SNH, CCo, SnFrB, WTR, MP

Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Jepson eFlora, Cal-IPC, and more.