Oryzopsis racemosa

HABIT Perennial; caespitose. Rhizomes short; knotty. Culms erect; 30–90 cm long. Leaves cauline. Leaf-sheaths antrorsely scabrous. Ligule a ciliolate membrane; 0.5 mm long. Leaf-blades 15–30 cm long; 8–15 mm wide. Leaf-blade surface scaberulous; rough abaxially; pubescent; hairy adaxially. Leaf-blade margins scabrous. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence a panicle.

Panicle open; elliptic; 5–30 cm long. Primary panicle branches ascending, or spreading; 5–11 cm long.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets elliptic; dorsally compressed; 7–8 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus pilose.

GLUMES Glumes persistent; similar; reaching apex of florets; thinner than fertile lemma. Lower glume oblong; 7–8 mm long; 1 length of upper glume; membranous; without keels; 7 -veined. Lower glume apex acute, or acuminate. Upper glume oblong; 7–8 mm long; 1 length of adjacent fertile lemma; membranous; without keels; 7 -veined. Upper glume apex acute, or acuminate.

FLORETS Fertile lemma oblong; dorsally compressed; 7–8 mm long; coriaceous; black; without keel. Lemma surface pubescent. Lemma margins convolute; covering most of palea. Lemma apex awned; 1 -awned. Principal lemma awn 10–25 mm long overall; deciduous. Palea coriaceous; 2 -veined; without keels.

FLOWER Anthers 4 mm long. Styles connate below.

FRUIT Caryopsis apex rostrate.

DISTRIBUTION North America: eastern Canada, north-central USA, northeast USA, and southeast USA.

NOTES Stipeae. Gr Indiana 1994.

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