Schizachyrium tenerum

HABIT Perennial; caespitose; clumped densely. Culms erect, or geniculately ascending; 40–110 cm long; 1–1.5 mm diam. Culm-nodes glabrous. Lateral branches sparse; arising from mid culm. Leaf-sheaths glabrous on surface. Ligule an eciliate membrane; 0.5–0.7 mm long. Leaf-blades 10–25 cm long; 1–2.5 mm wide. Leaf-blade midrib conspicuous; keeled beneath. Leaf-blade apex attenuate.

INFLORESCENCE Inflorescence composed of racemes; terminal and axillary. Peduncle 3–5 cm long.

Racemes 1; single; 3–10 cm long. Rhachis fragile at the nodes; semiterete; glabrous on margins. Rhachis internodes cuneate; 3.8–4.5 mm long. Rhachis internode tip crateriform; with scarious rim.

Spikelets appressed; in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels cuneate; 3.8–4.5 mm long; glabrous.

STERILE SPIKELETS Companion sterile spikelets well-developed; comprising 2 subequal glumes without lemmas; lanceolate; dorsally compressed; 4.7–5.7 mm long; as long as fertile; deciduous with the fertile. Companion sterile spikelet glumes coriaceous; 7 -veined; muticous.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets ovate; laterally compressed; 4.5–5 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus pilose; base obtuse; inserted.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume ovate; 1 length of spikelet; coriaceous; 2-keeled; keeled all along; keeled laterally; 7 -veined. Lower glume surface flat. Lower glume apex dentate; 2 -fid. Upper glume lanceolate; membranous; 1-keeled; 3 -veined. Upper glume primary vein scabrous.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret oblong; 3.2–4 mm long; hyaline; 2 -veined. Fertile lemma oblong; 3.5–4 mm long; hyaline; without keel; 1 -veined. Lemma margins ciliate. Lemma apex lobed; 2 -fid; incised 0.5 of lemma length; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 10 mm long overall; with twisted column. Column of lemma awn glabrous. Palea absent or minute.

FLOWER Anthers 2 mm long.

DISTRIBUTION North America: north-central USA, south-central USA, southeast USA, and Mexico. South America: Mesoamericana, Caribbean, northern South America, western South America, Brazil, and southern South America.

NOTES Andropogoneae. Gr Texas 1994.

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