GrassBase - The Online World Grass Flora


W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Schizachyrium occultum

HABIT Annual. Culms slender; 10–30 cm long; 0.3–0.5 mm diam.; 8–12 -noded. Lateral branches ample. Leaf-sheaths wider than blade at the collar; smooth. Ligule an eciliate membrane; 0.15–0.25 mm long. Leaf-blades conduplicate, or convolute; 1.5–3.5 cm long; 0.6–2 mm wide. Leaf-blade margins tuberculate-ciliate; hairy at base. Leaf-blade apex obtuse.

INFLORESCENCE Inflorescence composed of racemes; terminal and axillary; subtended by a spatheole; embraced at base by subtending leaf. Spatheole lanceolate; 1.5–3.7 cm long. Peduncle 0.2–0.4 cm long; glabrous, or pilose above.

Racemes 1; single; 1.2–2.7 cm long; 1.5 mm wide; bearing 5–10 fertile spikelets on each. Rhachis fragile at the nodes; semiterete; pubescent on surface. Rhachis internodes oblong; 3.5–5 mm long. Rhachis internode tip crateriform; with scarious 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 inflated; 3.5–5 mm long; ciliate.

STERILE SPIKELETS Companion sterile spikelets rudimentary; comprising 2 unequal glumes without lemmas; linear; 0.9–1.2 mm long; shorter than fertile; deciduous with the fertile. Companion sterile spikelet glumes chartaceous; ciliate on margins; awned; one glume awned; with 5–8 mm long awn.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; laterally compressed; acute; 3.75–5.1 mm long; 0.35–0.5 mm wide; falling entire; deciduous with accessory branch structures. Spikelet callus 0.45–0.65 mm long; pubescent; base obtuse; with elliptic scar. Spikelet callus hairs 1 mm long.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume lanceolate; 1 length of spikelet; chartaceous; 2-keeled; keeled above; keeled frontally. Lower glume primary vein scaberulous. Lower glume intercarinal veins obscure; 2 in number. Lower glume surface convex. Upper glume lanceolate; membranous; 1-keeled. Upper glume primary vein ciliate. Upper glume surface pubescent; hairy below. Upper glume apex acute; mucronate.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret oblong; 1 length of spikelet; hyaline; 0 -veined; without midvein; without lateral veins. Fertile lemma oblong; 3–3.5 mm long; hyaline; without keel; 1 -veined. Lemma apex lobed; 2 -fid; incised 0.9 of lemma length; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 9–13 mm long overall; with twisted column. Column of lemma awn 4–5 mm long; glabrous. Palea absent or minute.

FLOWER Anthers 0.4 mm long.

FRUIT Caryopsis with adherent pericarp; lanceolate; 2.6–3 mm long. Embryo 0.33 length of caryopsis.

DISTRIBUTION Australasia: Australia.

NOTES Andropogoneae. Blake 1994.

ADDITIONAL CHARACTERS Spikelet callus furrowed.

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