Sorghum ecarinatum

HABIT Annual. Butt sheaths glabrous, or pubescent. Culms 120–220 cm long; 2.3–6 mm diam.; without nodal roots, or with prop roots. Culm-internodes glaucous; distally pruinose, or glabrous. Culm-nodes glabrous, or pubescent. Lateral branches lacking, or sparse. Ligule an eciliate membrane; 2.5–5.8 mm long; glabrous on abaxial surface, or pubescent on abaxial surface. Leaf-blades 5–9 mm wide. Leaf-blade surface glabrous, or pilose, or hispid; with tubercle-based hairs.

INFLORESCENCE Inflorescence a panicle with branches tipped by a raceme.

Panicle open; dense, or loose; 15–30 cm long; 2–5 cm wide. Primary panicle branches 1–12 -nate; simple, or sparsely divided; 2.8–6.5 cm long. Panicle axis smooth. Panicle branches scabrous; rough distally; with scattered hairs, or pilose; hairy at tip; glabrous in axils, or pubescent in axils.

Racemes bearing a triad of spikelets, or few fertile spikelets; 1 fertile spikelets on each. Rhachis evident, or obsolete; tough (obsolete), or fragile at the nodes (below fertile spikelet); ciliate on margins. Rhachis internodes linear. Rhachis internode tip transverse.

Spikelets in pairs, or in threes. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 2 in the cluster. Pedicels filiform; flattened; 5.5–6 mm long; ciliate; with tawny hairs; with 3–3.3 mm long hairs.

STERILE SPIKELETS Basal sterile spikelets absent, or well-developed; 2 in number, or 4 in number; sessile and pedicelled; barren.

Companion sterile spikelets well-developed; containing empty lemmas, or male; lanceolate; dorsally compressed; 8–10 mm long; shorter than fertile; separately deciduous. Companion sterile spikelet glumes membranous; 8 -veined; glabrous, or pubescent; eciliate on margins, or ciliate on margins; acuminate; muticous. Companion sterile spikelet lemmas enclosed by glumes.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets oblong, or obovate; dorsally compressed; 9.5–11 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus cuneate; 3–4 mm long; base pungent.

GLUMES Glumes dissimilar; with lower wider than upper; exceeding apex of florets; firmer than fertile lemma. Lower glume ovate; 1 length of spikelet; coriaceous; much thinner above; dark brown, or black; without keels; keel-less throughout; 7 -veined. Lower glume lateral veins without connecting veins. Lower glume surface pubescent, or pilose. Lower glume apex obtuse. Upper glume ovate; coriaceous; much thinner above; dark brown, or black; without keels. Upper glume surface glabrous, or pubescent. Upper glume apex obtuse.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret lanceolate; hyaline; 2 -veined; acute. Fertile lemma oblong; hyaline; 1 -veined. Lemma apex lobed; 2 -fid; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 50–100 mm long overall; with twisted column. Column of lemma awn glabrous. Palea absent or minute.

FLOWER Lodicules 2; oblong; 0.6–0.7 mm long; fleshy; glabrous, or ciliate; hairy on the corners. Anthers 3. Stigmas 2.

FRUIT Caryopsis with adherent pericarp; obovoid; 4.5–5 mm long; obtuse.

DISTRIBUTION Australasia: Australia.

NOTES Andropogoneae. Lazarides 1993.

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