Themeda arundinacea

HABIT Perennial. Culms erect; 100–150 cm long. Culm-internodes solid. Leaf-sheaths keeled; glabrous on surface, or pubescent. Ligule a ciliolate membrane. Leaf-blades 30–60 cm long; 3–6 mm wide. Leaf-blade surface scabrous; rough adaxially; glabrous. Leaf-blade margins scabrous. Leaf-blade apex acuminate.

INFLORESCENCE Synflorescence compound; linear; 30–60 cm long; lax. Inflorescence composed of racemes; terminal and axillary; subtended by a spatheole; enclosed. Spatheole linear, or lanceolate; 4–4.5 cm long; scarious; without tubercles; glabrous.

Racemes 1; single; cuneate; bearing few fertile spikelets; bearing 1–2 fertile spikelets on each. Rhachis fragile at the nodes.

Spikelets in pairs, or in threes. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster, or 2 in the cluster. Pedicels oblong; 1 mm long; tip oblique.

STERILE SPIKELETS Basal sterile spikelets well-developed; 4 in number; forming an involucre about the fertile; with normal internodes; subsessile; 12–20 mm long; larger than fertile. Basal sterile spikelet glumes scarious; pilose; with red hairs; lower glume muticous.

Companion sterile spikelets well-developed; containing empty lemmas, or male; lanceolate; 10–15 mm long; as long as fertile, or longer than fertile; separately deciduous. Companion sterile spikelet callus linear; 2–2.5 mm long; truncate. Companion sterile spikelet glumes tuberculate; villous; with red hairs. 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; 10 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus cuneate; 2 mm long; pubescent; base pungent; attached obliquely. Spikelet callus hairs red.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume oblong; 1 length of spikelet; coriaceous; without keels. Lower glume surface pubescent. Lower glume hairs red. Upper glume oblong; coriaceous; 3 -veined. Upper glume surface pubescent. Upper glume hairs red.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret oblong; hyaline. Fertile lemma linear; hyaline; without keel; 1 -veined. Lemma apex entire; awned; 1 -awned. Principal lemma awn apical; geniculate; 35–70 mm long overall; with twisted column. Column of lemma awn hispidulous. Palea absent or minute.

DISTRIBUTION Asia-temperate: China. Asia-tropical: India, Indo-China, and Malesia.

NOTES Andropogoneae. Fl Assam 1993.

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