GrassBase - The Online World Grass Flora

Descriptions

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

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

Schizachyrium mexicanum

HABIT Perennial. Culms 60–90 cm long. Lateral branches sparse. Ligule an eciliate membrane; 2–4 mm long. Leaf-blades linear, or lanceolate; 10–15 cm long; 5–10 mm wide. Leaf-blade apex abruptly acute.

INFLORESCENCE Synflorescence compound; scanty; 20–25 cm long. Inflorescence composed of racemes; terminal and axillary; subtended by a spatheole. Spatheole linear; 2–2.5 cm long.

Racemes 1; single; 2–6 cm long; bearing 5–10 fertile spikelets on each. Rhachis fragile at the nodes; semiterete; ciliate on margins. Rhachis hairs 1–2.5 mm long. 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 filiform; 4.5–6 mm long; ciliate; with 1–2.5 mm long hairs.

STERILE SPIKELETS Companion sterile spikelets rudimentary; comprising 2 subequal glumes without lemmas, or containing empty lemmas, or male; linear; dorsally compressed; 1.5–2 mm long; shorter than fertile; deciduous with the fertile. Companion sterile spikelet glumes chartaceous; awned; one glume awned; with 1–1.5 mm long awn.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets linear; laterally compressed; 5–5.5 mm long; 0.7 mm wide; falling entire; deciduous with accessory branch structures. Spikelet callus base obtuse; inserted.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume linear; 1 length of spikelet; coriaceous; 2-keeled; keeled all along; keeled laterally. Lower glume surface convex. Upper glume lanceolate; membranous; 1-keeled.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret oblong; hyaline. Fertile lemma oblong; 1.5 mm long; hyaline; without keel; 1 -veined. Lemma apex lobed; 2 -fid; incised 0.66 of lemma length; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 10–15 mm long overall; with twisted column. Column of lemma awn glabrous. Palea absent or minute.

FLOWER Anthers 1.5–2 mm long.

DISTRIBUTION North America: Mexico.

NOTES Andropogoneae. Fl Nov Gal 1994.

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