GrassBase - The Online World Grass Flora


W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Sorghum angustum

HABIT Annual. Culms erect; 50–100 cm long; 3–6 -noded; without nodal roots, or with prop roots. Culm-nodes bearded. Leaves cauline. Leaf-sheath oral hairs bearded. Ligule a ciliolate membrane; 0.6–1 mm long. Leaf-blades 8–46 cm long; 2–5.6 mm wide. Leaf-blade surface glabrous, or hirsute; with tubercle-based hairs. Leaf-blade apex attenuate; filiform.

INFLORESCENCE Inflorescence a panicle with branches tipped by a raceme.

Panicle open; lanceolate; loose; 9.5–20 cm long. Primary panicle branches drooping; 1–2(–4) -nate; whorled at lower nodes; simple; 2–9 cm long. Panicle branches capillary; bearded in axils; with prominent pulvini.

Racemes 1–2(–4) cm long; bearing few fertile spikelets; bearing 1–2(–4) fertile spikelets on each. Rhachis fragile at the nodes; ciliate on margins. Rhachis hairs white, or dark brown, or red. Rhachis internodes linear; 4–6 mm long. Rhachis internode tip oblique.

Spikelets in pairs, or in threes. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster, or 2 in the cluster. Pedicels linear; ciliate.

STERILE SPIKELETS Companion sterile spikelets represented by barren pedicels.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets oblanceolate; dorsally compressed; 10.7–13 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus linear; curved; 3.5–7 mm long; pilose; base pungent; attached obliquely. Spikelet callus hairs white, or red.

GLUMES Glumes dissimilar; with lower wider than upper; exceeding apex of florets; firmer than fertile lemma; dull, or shiny. Lower glume elliptic; 1 length of spikelet; coriaceous; without keels; keel-less except near apex; 9–11 -veined. Lower glume surface glabrous, or hispid, or villous. Lower glume apex acute. Upper glume ovate; coriaceous; without keels; 7–9 -veined. Upper glume surface glabrous, or pilose.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret elliptic; 0.8 length of spikelet; hyaline; 2 -veined; ciliolate on margins. Fertile lemma oblong; 3.7–4.2 mm long; hyaline; 1 -veined. Lemma margins ciliate. Lemma apex dentate; 2 -fid; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 37–85(–114) mm long overall; with twisted column. Column of lemma awn pubescent; hairy on the spiral. Palea absent or minute.

FLOWER Lodicules 2; ciliate. Anthers 3; 2.5 mm long.

FRUIT Caryopsis with adherent pericarp; oblong; 3.3 mm long.

DISTRIBUTION Australasia: Australia.

NOTES Andropogoneae. Lazarides.

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