Iseilema thorelii

HABIT Perennial. Culms erect; 90–130 cm long. Culm-nodes bearded. Leaf-sheaths keeled; glabrous on surface. Ligule an eciliate membrane. Leaf-blades 20–30 cm long; 2.5–5 mm wide. Leaf-blade midrib keeled beneath. Leaf-blade surface scaberulous; rough abaxially. Leaf-blade margins scaberulous. Leaf-blade apex acute, or acuminate.

INFLORESCENCE Synflorescence compound; linear; 18–30 cm long. Inflorescence composed of racemes; terminal and axillary; deciduous as a whole; subtended by a spatheole; enclosed. Spatheole lanceolate; 0.8–1 cm long; herbaceous; tuberculate (on midnerve). Peduncle 0.2 cm long; pilose above.

Racemes 1; single; oblong; 0.6 cm long; bearing few fertile spikelets; bearing 1 fertile spikelets on each. Rhachis internodes linear; 1 mm long. Raceme-bases brief (truncate).

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

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; pedicelled; deciduous with the fertile. Basal sterile spikelet pedicels linear; 0.5–1 mm long. Basal sterile spikelets male; oblong; 4.5–5 mm long; equalling fertile. Basal sterile spikelet glumes herbaceous; tuberculate on margins.

Companion sterile spikelets well-developed; male; linear, or oblong; 4 mm long; shorter than fertile; separately deciduous. Companion sterile spikelet glumes chartaceous; tuberculate; glabrous; muticous. Companion sterile spikelet lemmas 2; enclosed by glumes.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets linear, or oblong; dorsally compressed; 5 mm long; falling entire; deciduous with accessory branch structures.

GLUMES Glumes dissimilar; firmer than fertile lemma. Lower glume elliptic; 1 length of spikelet; coriaceous; without keels; keel-less except near apex. Lower glume primary vein scabrous. Lower glume apex truncate. Upper glume lanceolate; 1 length of spikelet; coriaceous.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret hyaline. Fertile florets female. Fertile lemma linear; membranous; 1 -veined. Lemma apex entire; awned; 1 -awned. Principal lemma awn geniculate; 8–10 mm long overall; with twisted column. Column of lemma awn glabrous. Palea absent or minute.

DISTRIBUTION Asia-tropical: Indo-China and Malesia.

NOTES Andropogoneae. Camus.

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