Schizachyrium condensatum

HABIT Perennial; caespitose. Culms erect; 90–150 cm long; 2–3.5 mm diam. Culm-internodes elliptical in section; solid. Culm-nodes glabrous. Lateral branches ample. Leaf-sheaths keeled; glabrous on surface. Ligule an eciliate membrane; 0.7–2 mm long. Leaf-blades 20–40 cm long; 3–8 mm wide. Leaf-blade midrib keeled beneath.

INFLORESCENCE Synflorescence compound; linear, or paniculate, or globose; 20–40 cm long; dense, or lax. Inflorescence composed of racemes; terminal and axillary; subtended by a spatheole; embraced at base by subtending leaf. Spatheole linear; 1.5–3.5 cm long; herbaceous. Peduncle 2.5–6 cm long.

Racemes 1; single; sinuous; 2–4 cm long; bearing 6–8 fertile spikelets on each. Rhachis fragile at the nodes; subterete; plumose on margins. Rhachis internodes clavate; 4–6 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 clavate; curved; 3.6–5.5 mm long; plumose.

STERILE SPIKELETS Companion sterile spikelets well-developed; comprising 2 subequal glumes without lemmas; linear; dorsally compressed; 1–2 mm long; shorter than fertile; deciduous with the fertile. Companion sterile spikelet glumes herbaceous; awned; one glume awned; with 0.5–2 mm long awn.

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

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume lanceolate; 1 length of spikelet; chartaceous; 2-keeled; keeled all along; keeled laterally; keeled sharply. Lower glume intercarinal veins absent. Lower glume surface convex; glabrous. Lower glume apex emarginate. Upper glume lanceolate; membranous; 1-keeled; 3 -veined. Upper glume primary vein scabrous. Upper glume apex acute.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret oblong; 3.2–3.8 mm long; hyaline; 0 -veined; without midvein; without lateral veins; ciliolate on margins. Fertile lemma linear; 3–4 mm long; hyaline; without keel; 1 -veined. Lemma margins ciliolate. Lemma apex lobed; 2 -fid; incised 0.75 of lemma length; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 8–15 mm long overall; with twisted column. Column of lemma awn glabrous. Palea absent or minute.

FRUIT Caryopsis with adherent pericarp; linear; 2.5–2.8 mm long.

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

NOTES Andropogoneae. Wagner 1993.

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