Iseilema calvum

HABIT Annual; caespitose. Culms erect, or geniculately ascending; 15–40 cm long; 4–6 -noded. Lateral branches ample. Leaf-sheaths keeled. Ligule a ciliolate membrane; 1 mm long. Leaf-blades conduplicate; 10–25 cm long; 3–6 mm wide; glaucous. Leaf-blade margins scabrous. Leaf-blade apex acute.

INFLORESCENCE Synflorescence compound; linear; 4–25 cm long. Inflorescence composed of racemes; terminal and axillary; deciduous as a whole; subtended by a spatheole; enclosed. Spatheole elliptic; 1.2–1.7 cm long; chartaceous; without tubercles. Peduncle 0.3–0.6 cm long; scaberulous above.

Racemes 1; single; oblong; 0.7–0.9 cm long; bearing few fertile spikelets; bearing 1 fertile spikelets on each. Rhachis glabrous on surface. Rhachis internodes linear; 0.5 mm long. Raceme-bases brief (truncate); glabrous.

Spikelets in threes (basal paired). Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 2 in the cluster. Pedicels filiform; 3.5–4 mm long; scaberulous.

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; 0.8–1 mm long. Basal sterile spikelets male; oblong; 5.5–6.5 mm long; equalling fertile. Basal sterile spikelet glumes cartilaginous; glabrous.

Companion sterile spikelets well-developed; male; lanceolate, or elliptic; 3–5 mm long; shorter than fertile; separately deciduous. Companion sterile spikelet glumes membranous; 11–13 -veined; scaberulous; 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 lanceolate; dorsally compressed; acuminate; 6–7 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; 8–12 -veined. Lower glume surface convex. Lower glume apex truncate. Upper glume lanceolate; 1 length of spikelet; coriaceous; 3 -veined. Upper glume apex acuminate.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret lanceolate; 5.5–6 mm long; membranous; 3 -veined. Fertile florets female. Fertile lemma linear; 3–5 mm long; membranous; 1 -veined. Lemma apex entire; awned; 1 -awned. Principal lemma awn geniculate; 15–22 mm long overall; with twisted column. Column of lemma awn 5–10 mm long; glabrous. Palea absent or minute.

FLOWER Anthers 3; 1.5 mm long.

FRUIT Caryopsis oblong, or obovoid; 3 mm long.

DISTRIBUTION Australasia: Australia.

NOTES Andropogoneae. CEH.

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