Iseilema argutum

HABIT Annual. Basal innovations flabellate. Culms erect; 10–30 cm long. Culm-nodes bearded. Ligule an eciliate membrane; 0.5 mm long. Leaf-blades 2–6 cm long; 2–3 mm wide. Leaf-blade apex obtuse.

INFLORESCENCE Synflorescence compound; scanty; 3–15 cm long. Inflorescence composed of racemes; terminal and axillary; deciduous as a whole; subtended by a spatheole; enclosed. Spatheole lanceolate; 1–1.2 cm long; herbaceous; tuberculate (on midnerve & margin).

Racemes 1; single; oblong; bearing few fertile spikelets; bearing 1 fertile spikelets on each. Rhachis internodes filiform; 1 mm long (below fertile spikelet). Raceme-bases brief (truncate); hirsute.

Spikelets in threes (basal paired). Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 2 in the cluster. Pedicels filiform; 3 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 oblong; 0.5–1 mm long. Basal sterile spikelets male; elliptic; 5 mm long; smaller than fertile. Basal sterile spikelet glumes herbaceous.

Companion sterile spikelets well-developed; comprising 2 subequal glumes without lemmas; linear; 2 mm long; shorter than fertile; separately deciduous. Companion sterile spikelet glumes chartaceous; glabrous; muticous.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; dorsally compressed; rostrate; 6 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus bearded. Spikelet callus hairs 3 mm long.

GLUMES Glumes dissimilar; firmer than fertile lemma; shiny. Lower glume elliptic; 1 length of spikelet; coriaceous; without keels; keel-less except near apex. Lower glume apex obtuse. 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; 18–20 mm long overall; with twisted column. Column of lemma awn glabrous. Palea absent or minute.

DISTRIBUTION Asia-tropical: Indo-China and Malesia.

NOTES Andropogoneae. WDC.

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