Avena sativa oats Poaceae AVSA*; Bx, pb; Q, j; R ar;

Avena sativa (oats). commons.wikimedia.org

Avena sativa (oats). commons.wikimedia.org (Accessed10/2017).

Avena sativa  is an annual C3 grass (Pascal-Antoine 2008) to 1 m tall. 

Leaves alternate, ligules 0.2-0.6 cm membranous, blade rough, to slightly hairy, 0.3-1 cm wide. 

Avena sativa. spikelet labeled. By Anna Gardner. Copyright © 2017.  Ada Hayden Herbarium - Iowa State U. New England Wild Flower Society. gobotany.newenglandwild.org

Avena sativa. spikelet labeled. By Anna Gardner. Copyright © 2017. Ada Hayden Herbarium – Iowa State U. New England Wild Flower Society. gobotany.newenglandwild.org (Accessed 10/2017).

Flowers: Spiklets 2 flowered, nodding, axis smooth, glumes 2- 2.5 cm long, with 9-11 veins; lemma 1.5-2 cm, hard, sometimes awned, 2.5-3.5 cm long; inflorescence 10-25 cm or more, open, branches horizontal; blooming and fruiting July-Oct. 

Wetland status: UPL. 

Frequency in NYC: Very infrequent. 

Origin: Eurasia. 

Avena sativa black oat, zwarte haver. ripe inflorescence. commons.wikimedia.org

Avena sativa black oat, zwarte haver. ripe inflorescence. commons.wikimedia.org (Accessed 10/2017).

Habitat: Disturbed sites. Sometimes introduced from hay bales at construction sites. Generally not persistent (Gargiullo personal observation).