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 pachyarthron

HABIT Annual. Culms 50–100 cm long; 0.5–2 mm diam.; 5–13 -noded. Lateral branches ample. Leaf-sheaths wider than blade at the collar; smooth, or scaberulous. Ligule an eciliate membrane; 0.2–0.6 mm long. Leaf-blades conduplicate; 1.5–10 cm long; 0.8–3 mm wide. Leaf-blade margins scaberulous; 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 linear; 2.5–6 cm long. Peduncle 0.4–0.8 cm long.

Racemes 1; single; 3–5 cm long; 1.5–2 mm wide; bearing 6–10 fertile spikelets on each. Rhachis fragile at the nodes; semiterete; pilose on surface; ciliate on margins. Rhachis internodes clavate; 5–8 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 linear; 4.5–8 mm long; ciliate.

STERILE SPIKELETS Companion sterile spikelets rudimentary; comprising 2 unequal glumes without lemmas; linear; 1.5–3 mm long; shorter than fertile; deciduous with the fertile. Companion sterile spikelet glumes chartaceous; ciliolate on margins, or ciliate on margins; awned; one glume awned; with 10–30 mm long awn.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets oblong; dorsally compressed; obtuse; 5–8 mm long; 1.3–1.6 mm wide; falling entire; deciduous with accessory branch structures. Spikelet callus 0.4–1 mm long; pubescent; base obtuse; with circular scar, or 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; coriaceous; 2-keeled; keeled all along; keeled laterally; winged on keel; winged narrowly; winged all along. Lower glume intercarinal veins distinct; 5 in number. Lower glume surface convex; glabrous, or pilose; hairy at apex. Lower glume hairs 3–4.5 mm long. Upper glume lanceolate; membranous; 1-keeled; wingless, or winged on keel; winged above. Upper glume surface glabrous, or pubescent.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret oblong; 0.75–1 length of spikelet; hyaline; 2 -veined. Fertile lemma oblong; 4–6 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; 19–30 mm long overall; with twisted column. Column of lemma awn 8.5–11 mm long; glabrous. Palea absent or minute.

FLOWER Anthers 0.5–0.7 mm long.

FRUIT Caryopsis with adherent pericarp; ellipsoid, or oblong; 2.3–3.5 mm long; obtuse. Embryo 0.4–0.5 length of caryopsis.

DISTRIBUTION Australasia: Australia.

NOTES Andropogoneae. Blake 1994.

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