Themeda laxa

HABIT Perennial; caespitose. Culms erect; 60–120 cm long. Lateral branches ample. Ligule absent. Leaf-blades 7–15 cm long; 3–5 mm wide. Leaf-blade surface pilose; sparsely hairy; hairy abaxially. Leaf-blade margins scabrous; ciliate (hairs 4–5mm).

INFLORESCENCE Synflorescence compound; paniculate. Inflorescence composed of racemes; terminal and axillary; subtended by a spatheole; enclosed. Spatheole lanceolate; 2.5–3.5 cm long; scarious; without tubercles; glabrous.

Racemes 1; single; cuneate; bearing few fertile spikelets; bearing 1 fertile spikelets on each. Rhachis fragile at the nodes.

Spikelets in threes (basal paired). Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 2 in the cluster. Pedicels oblong; 0.5 mm long; tip oblique.

STERILE SPIKELETS Basal sterile spikelets well-developed; 4 in number; forming an involucre about the fertile; with both pairs arising at about the same level; subsessile; barren, or male; oblong; 5–6 mm long; larger than fertile. Basal sterile spikelet glumes tuberculate; tuberculate on margins; lower glume muticous.

Companion sterile spikelets well-developed; containing empty lemmas, or male; linear; 2.5 mm long; shorter than fertile; separately deciduous. Companion sterile spikelet callus linear; 2–3 mm long. Companion sterile spikelet glumes herbaceous; ciliate on margins; acute. Companion sterile spikelet lemmas 2; enclosed by glumes.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; subterete; 4.25 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus cuneate; 1 mm long; pubescent; base acute; attached obliquely. Spikelet callus hairs dark brown.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume oblong; 1 length of spikelet; coriaceous; without keels; 9 -veined. Lower glume surface scabrous; rough above. Lower glume apex truncate. Upper glume oblong; coriaceous; 3 -veined.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret linear; 3 mm long; hyaline. Fertile lemma linear; 1 mm long; hyaline; without keel; 1 -veined. Lemma apex entire; awned; 1 -awned. Principal lemma awn apical; geniculate; 30–35 mm long overall; with twisted column. Column of lemma awn hispidulous. Palea absent or minute.

DISTRIBUTION Asia-tropical: India.

NOTES Andropogoneae. Fl Assam 1993.

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