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.

Andropogon brachystachyus

HABIT Perennial; caespitose. Culms 60–150 cm long. Culm-internodes distally pilose. Lateral branches ample. Leaf-sheaths keeled; smooth; glabrous on surface. Ligule an eciliate membrane. Leaf-blades erect; conduplicate; 15–30 cm long; 3–4 mm wide. Leaf-blade surface scabrous; rough adaxially.

INFLORESCENCE Synflorescence compound; linear, or paniculate. Inflorescence composed of racemes; terminal and axillary; subtended by a spatheole; exserted, or embraced at base by subtending leaf. Spatheole linear; 3–3.5 cm long.

Racemes 2; paired; 1–2 cm long; bearing 4–6 fertile spikelets on each. Rhachis fragile at the nodes; villous on margins. Rhachis hairs 3 mm long. Rhachis internodes filiform; 1.5–2 mm long. Rhachis internode tip transverse; cupuliform; with simple rim.

Spikelets in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels filiform; curved; 2.5–4 mm long; villous; with 3 mm long hairs.

STERILE SPIKELETS Companion sterile spikelets represented by barren pedicels.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; dorsally compressed; 3–4.5 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus bearded; base obtuse; inserted.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume lanceolate; 1 length of spikelet; cartilaginous; 2-keeled; keeled laterally. Lower glume intercarinal veins absent. Lower glume surface flat, or concave; pubescent. Upper glume lanceolate; membranous; 1-keeled. Upper glume muticous.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret oblong; hyaline. Fertile lemma lanceolate; hyaline; without keel. Lemma apex lobed; 2 -fid; awned; 1 -awned. Principal lemma awn from a sinus; straight; 6–9 mm long overall.

FLOWER Anthers 1.

DISTRIBUTION North America: southeast USA.

NOTES Andropogoneae. N Amer Fl 1994.

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