Schizachyrium sulcatum

HABIT Annual. Culms rambling, or prostrate; slender; 5–60 cm long; 0.7–1 mm diam.; 11–15 -noded. Leaf-sheaths mostly shorter than adjacent culm internode. Ligule a ciliolate membrane. Leaf-blades 1–6 cm long; 2–4 mm wide. Leaf-blade apex obtuse.

INFLORESCENCE Synflorescence compound; scanty. Inflorescence composed of racemes; terminal and axillary; subtended by a spatheole; embraced at base by subtending leaf. Spatheole linear; 2–3 cm long.

Racemes 1; single; 3 cm long; 0.5 mm wide; bearing 9–12 fertile spikelets on each. Rhachis fragile at the nodes; semiterete; ciliate on margins. Rhachis internodes clavate; 2.5–3 mm long. Rhachis internode tip cupuliform; with simple rim.

Spikelets squeezed between internode and pedicel; in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels linear; 2.5–3 mm long; ciliate; tip widened.

STERILE SPIKELETS Companion sterile spikelets rudimentary; lanceolate; dorsally compressed; 0.7–1 mm long; shorter than fertile; deciduous with the fertile. Companion sterile spikelet glumes chartaceous; awned; one glume awned; with 1.5 mm long awn.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; subterete; 3–3.6 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus 0.15 mm long; glabrous; base obtuse; inserted.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume lanceolate; 1 length of spikelet; coriaceous; 2-keeled; keeled above; keeled frontally. Lower glume intercarinal veins distinct; 2 in number. Lower glume surface with a longitudinal median groove; asperulous. Upper glume lanceolate; membranous; 1-keeled. Upper glume apex acuminate.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret oblong; hyaline; 2 -veined. Fertile lemma oblong; hyaline; without keel. Lemma apex lobed; 2 -fid; incised 0.9 of lemma length; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 5–7 mm long overall; with twisted column. Column of lemma awn 2.5–4 mm long; glabrous. Palea absent or minute.

FLOWER Anthers 3.

FRUIT Caryopsis with adherent pericarp; 2.3 mm long.

DISTRIBUTION South America: western South America and Brazil.

NOTES Andropogoneae. Blake 1994.

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