GrassBase - The Online World Grass Flora

Descriptions

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

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

Sorghum controversum

HABIT Perennial; caespitose. Rhizomes elongated. Culms erect; 50–200 cm long; 3–10 mm diam. Culm-nodes glabrous, or pubescent. Lateral branches lacking. Leaf-sheaths 7–15 cm long; glabrous on surface. Ligule a ciliolate membrane. Leaf-blades 25–60 cm long; 8–22 mm wide. Leaf-blade surface glabrous.

INFLORESCENCE Inflorescence a panicle with branches tipped by a raceme.

Panicle open; ovate, or pyramidal; 15–30 cm long; 5–15 cm wide. Primary panicle branches 3–4 -nate; whorled at lower nodes; 5–16 cm long. Panicle branches flexuous; pubescent in axils.

Racemes 0.8–2.2 cm long; bearing few fertile spikelets; bearing 2–5 fertile spikelets on each. Rhachis fragile at the nodes; ciliate on margins. Rhachis hairs white, or tawny; 0.7–1 mm long. Rhachis internodes linear; 2–4 mm long. Rhachis internode tip transverse.

Spikelets in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels filiform; flattened; 2–4 mm long; ciliate.

STERILE SPIKELETS Companion sterile spikelets well-developed; male; linear, or lanceolate; dorsally compressed; 6–6.25 mm long; longer than fertile; separately deciduous. Companion sterile spikelet glumes chartaceous; 7–9 -veined; pubescent; muticous. Companion sterile spikelet lemmas enclosed by glumes.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; dorsally compressed; acute, or acuminate; 5–6.2 mm long; 1.5–2.7 mm wide; falling entire; deciduous with accessory branch structures. Spikelet callus pilose; 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; chartaceous; much thinner above; without keels; keel-less except near apex; 9–11 -veined. Lower glume surface pubescent. Lower glume margins ciliolate. Lower glume apex emarginate, or acute. Upper glume ovate; chartaceous; much thinner above; without keels; 7 -veined. Upper glume margins scaberulous; ciliolate.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret oblong; 4.5–4.7 mm long; hyaline; 2 -veined; ciliolate on margins; acute. Fertile lemma oblong; 3–4 mm long; hyaline; 1 -veined. Lemma margins ciliolate. Lemma apex lobed; 2 -fid; incised 0.25–0.33 of lemma length; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 10–14 mm long overall; with twisted column. Column of lemma awn glabrous. Palea lanceolate; 2.5–3 mm long; hyaline; 0 -veined.

FLOWER Lodicules 2; oblong; fleshy; ciliate. Anthers 3; 3–3.75 mm long. Stigmas 2.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION Asia-tropical: India.

NOTES Andropogoneae. Snowden 1993.

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