Tridens oklahomensis

HABIT Perennial; caespitose; clumped densely. Culms erect; robust; 120–150 cm long. Ligule a fringe of hairs. Leaf-blades 30–60 cm long; 6–12 mm wide. Leaf-blade surface glabrous; hairless throughout, or except near base.

INFLORESCENCE Inflorescence a panicle; terminal and axillary.

Panicle open; oblong; 20–25 cm long; contracted about primary branches. Primary panicle branches ascending; bearing spikelets almost to the base. Panicle branches stiff; straight; viscid.

Spikelets appressed, or ascending; solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 7–9 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 6–8 mm long; breaking up at maturity; disarticulating below each fertile floret.

GLUMES Glumes persistent; similar; shorter than spikelet; thinner than fertile lemma. Lower glume ovate; 4 mm long; 1 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume apex acute. Upper glume ovate; 4 mm long; 1 length of adjacent fertile lemma; membranous; 1-keeled; 1 -veined. Upper glume lateral veins absent. Upper glume apex acute.

FLORETS Fertile lemma elliptic; 4 mm long; chartaceous; without keel; 3 -veined. Lemma midvein pubescent. Lemma lateral veins close to margins; excurrent. Lemma margins pubescent. Lemma apex dentate; 2 -fid; mucronate. Palea bowed outwards; 0.9 length of lemma. Apical sterile florets resembling fertile though underdeveloped.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION North America: north-central USA.

NOTES Eragrostideae. Man US Gr 1997.

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