Sphenopholis obtusata

HABIT Annual, or perennial; caespitose. Culms 20–70(–120) cm long. Ligule an eciliate membrane; 1.5–3 mm long. Leaf-blades 4–10(–15) cm long (basal blades); 2–8 mm wide.

INFLORESCENCE Inflorescence a panicle.

Panicle open, or contracted; lanceolate; 5–25 cm long. Primary panicle branches appressed.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels linear; 0.2–2 mm long.

FERTILE SPIKELETS Spikelets comprising 2–3 fertile florets; with a barren rhachilla extension. Spikelets obovate; laterally compressed; 1.5–5 mm long; falling entire. Rhachilla internodes 0.3–1.2 mm long; smooth, or scaberulous.

GLUMES Glumes dissimilar; with lower narrower than upper; shorter than spikelet; gaping. Lower glume lanceolate; 1–4 mm long; 0.9 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume primary vein smooth, or scaberulous. Lower glume lateral veins absent. Lower glume apex acute. Upper glume obovate; 1.2–4.2 mm long; 0.8 length of adjacent fertile lemma; membranous; 1-keeled; 3 -veined. Upper glume primary vein scaberulous. Upper glume surface smooth, or asperulous; rough on veins. Upper glume apex obtuse, or acute.

FLORETS Fertile lemma ovate; 1.4–4.4 mm long; membranous; keeled; 5 -veined. Lemma surface smooth, or scaberulous. Lemma apex obtuse, or acute. Palea gaping; 0.8 length of lemma. Palea keels scaberulous. Rhachilla extension 0.75 length of fertile floret.

FLOWER Ovary glabrous.

FRUIT Caryopsis with adherent pericarp; oblong; glabrous. Endosperm liquid.

DISTRIBUTION Pacific: north-central. North America: western Canada, northwest USA, north-central USA, northeast USA, southwest USA, south-central USA, southeast USA, and Mexico. South America: Caribbean.

NOTES Aveneae. Erdman.

ADDITIONAL CHARACTERS Lower glume less than 0.33 width of upper.

Please cite this publication as detailed in How to Cite Version: 3rd February 2016.