Iseilema vaginiflorum

HABIT Annual; caespitose. Culms erect, or geniculately ascending; 45–75 cm long. Leaf-sheaths keeled. Ligule a ciliolate membrane; 0.5–1 mm long. Leaf-blades flat, or conduplicate; 10–20 cm long; 2.5–6 mm wide.

INFLORESCENCE Synflorescence compound; linear; 10–22 cm long; with principal spatheoles embracing a compact fascicle of racemes, each subtended by a subsidiary bract. Inflorescence composed of racemes; terminal and axillary; deciduous as a whole; subtended by a spatheole; enclosed. Spatheole lanceolate; 0.9–1.2 cm long; coriaceous; without tubercles. Peduncle 1–2 cm long; disarticulating; disarticulating below uppermost sheaths (raceme eventually disarticulating).

Racemes 1; single; oblong; 0.7–0.8 cm long; bearing few fertile spikelets; bearing 1 fertile spikelets on each. Rhachis hairs mainly at internode tip; 1–2 mm long. Rhachis internodes linear; 1 mm long. Raceme-bases brief (truncate); glabrous, or pilose; with 1–1.5 mm long hairs.

Spikelets in threes. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 2 in the cluster. Pedicels filiform; 2.5–3 mm long; glabrous, or pubescent.

STERILE SPIKELETS Basal sterile spikelets represented by a single scale, or rudimentary; 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 1–1.5 mm long. Basal sterile spikelets oblong; 2–4 mm long; smaller than fertile. Basal sterile spikelet glumes membranous; smooth, or scaberulous.

Companion sterile spikelets well-developed; containing empty lemmas, or male; lanceolate, or oblong; 3–5 mm long; shorter than fertile; separately deciduous. Companion sterile spikelet glumes cartilaginous; 5–7 -veined; glabrous; muticous.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; dorsally compressed; 6.5–7 mm long; falling entire; deciduous with accessory branch structures.

GLUMES Glumes dissimilar; firmer than fertile lemma. Lower glume lanceolate; 1 length of spikelet; coriaceous; without keels; keel-less except near apex; 8–10 -veined. Lower glume apex dentate; 2 -fid. 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 oblong; 3.5–4 mm long; hyaline; 0 -veined; without midvein; without lateral veins. Fertile florets female. Fertile lemma linear; 4–5.5 mm long; membranous; 1 -veined. Lemma apex entire; awned; 1 -awned. Principal lemma awn geniculate; 15–23 mm long overall; with twisted column. Column of lemma awn 6–9 mm long; glabrous. Palea absent or minute.

FLOWER Anthers 3; 1–2 mm long.

FRUIT Caryopsis with adherent pericarp; 2.5–3 mm long.

DISTRIBUTION Australasia: Australia.

NOTES Andropogoneae. Vickery.

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