Sorghum halepense

HABIT Perennial. Rhizomes elongated; scaly. Culms erect, or geniculately ascending, or decumbent; 50–300 cm long. Culm-nodes pubescent. Leaves cauline. Ligule a ciliolate membrane. Leaf-blades 20–90 cm long; 5–40 mm wide. Leaf-blade margins scaberulous.

INFLORESCENCE Inflorescence a panicle with branches tipped by a raceme.

Panicle open; lanceolate, or pyramidal; 10–55 cm long; 3–25 cm wide. Primary panicle branches whorled at most nodes; moderately divided.

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; ciliate.

STERILE SPIKELETS Companion sterile spikelets well-developed; male; lanceolate; 4.5–6.5 mm long; as long as fertile; separately deciduous. Companion sterile spikelet glumes chartaceous; 5 -veined; 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; 4.5–5(–5.5) 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 elliptic; 1 length of spikelet; coriaceous; pallid, or dark brown, or red, or purple, or black; 2-keeled; keeled above. Lower glume surface glabrous, or pubescent. Lower glume apex dentate; 3 -fid. Upper glume ovate; coriaceous; without keels. Upper glume surface glabrous, or pubescent.

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 elliptic; 2–2.5 mm long; hyaline; 1 -veined. Lemma margins ciliate. Lemma apex entire, or dentate; 2 -fid; muticous, or awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 10–16 mm long overall; with twisted column. Column of lemma awn pubescent; hairy on the spiral. Palea present.

FLOWER Lodicules 2; ciliate.

DISTRIBUTION Europe: central, southwestern, southeastern, and eastern. Africa: north, Macaronesia, west tropical, west-central tropical, northeast tropical, southern tropical, south, and western Indian ocean. Asia-temperate: Soviet Middle Asia, Caucasus, western Asia, Arabia, China, and eastern Asia. Asia-tropical: India, Indo-China, Malesia, and Papuasia. Australasia: Australia and New Zealand. Pacific: southwestern, south-central, northwestern, and north-central. North America: northwest USA, north-central USA, northeast USA, southwest USA, south-central USA, southeast USA, and Mexico. South America: Mesoamericana, Caribbean, northern South America, western South America, Brazil, and southern South America.

NOTES Andropogoneae. Fl Pak.

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