Sorghum almum

HABIT Perennial. Rhizomes short. Culms erect; 200–320 cm long; 6–10 mm diam.; 8–10 -noded. Culm-internodes solid; 7–40 cm long; smooth; distally glabrous. Culm-nodes pubescent. Leaves cauline. Leaf-sheaths smooth; glabrous on surface. Leaf-sheath oral hairs ciliate. Ligule a ciliolate membrane; 2.5–3.5 mm long. Leaf-blades 30–100 cm long; 25–40 mm wide. Leaf-blade surface smooth; glabrous. Leaf-blade margins scaberulous. Leaf-blade apex attenuate.

INFLORESCENCE Inflorescence a panicle with branches tipped by a raceme; terminal, or terminal and axillary.

Panicle open; pyramidal; 20–60 cm long; 8–25 cm wide. Primary panicle branches 4–9 -nate; whorled at most nodes; 10–15 cm long.

Racemes 1.2–2.5 cm long; bearing few fertile spikelets; bearing 1–5 fertile spikelets on each. Rhachis fragile at the nodes; ciliate on margins. Rhachis internodes filiform. Rhachis internode tip transverse; cupuliform.

Spikelets in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels filiform; 3–3.5 mm long; ciliate.

STERILE SPIKELETS Companion sterile spikelets well-developed; male; lanceolate; 5 mm long; shorter than fertile, or as long as fertile; persistent, or separately deciduous. Companion sterile spikelet glumes chartaceous; 9 -veined; muticous. Companion sterile spikelet lemmas enclosed by glumes.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets ovate; dorsally compressed; 5.5–6.5 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus pubescent; base obtuse.

GLUMES Glumes dissimilar; with lower wider than upper; exceeding apex of florets; firmer than fertile lemma. Lower glume ovate; 1 length of spikelet; coriaceous; dark brown; 2-keeled; keeled above; 9–11 -veined. Lower glume surface flat; pubescent; hairy below. Lower glume hairs 0.5–0.8 mm long. Lower glume apex dentate; 3 -fid. Upper glume ovate; coriaceous; without keels. Upper glume surface pubescent; hairy below.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret elliptic; hyaline; 2 -veined; ciliolate on margins. Fertile lemma elliptic; hyaline; 1 -veined. Lemma margins ciliolate. Lemma apex entire, or dentate; 2 -fid; muticous, or awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 8–10 mm long overall; with twisted column; deciduous.

FLOWER Anthers 3; 2–2.5 mm long.

FRUIT Caryopsis with adherent pericarp; obovoid; 3–3.8 mm long; dark brown. Embryo 0.5 length of caryopsis.

DISTRIBUTION Africa: western Indian ocean. Australasia: Australia. South America: southern South America.

NOTES Andropogoneae. Parodi 1997.

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