Heteropogon melanocarpus

HABIT Annual. Culms erect; robust; 50–250 cm long; with prop roots. Leaves cauline. Leaf-sheaths glandular. Ligule an eciliate membrane. Leaf-blades 15–50 cm long; 4–10 mm wide. Leaf-blade apex attenuate.

INFLORESCENCE Synflorescence compound; paniculate; 10–30 cm long. Inflorescence composed of racemes; terminal and axillary; subtended by a spatheole; enclosed. Spatheole linear; 7–12 cm long; herbaceous.

Racemes 1; single; unilateral; 3–6 cm long. Rhachis fragile at the nodes; glabrous on margins. Rhachis internodes linear; 2–3 mm long. Rhachis internode tip oblique.

Spikelets appressed; in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels oblong; semiterete; 0.2 length of fertile spikelet.

STERILE SPIKELETS Basal sterile spikelets well-developed; 2–6 in number; larger than fertile.

Companion sterile spikelets well-developed; male; lanceolate; asymmetrical; dorsally compressed; 15–25 mm long; longer than fertile; separately deciduous. Companion sterile spikelet callus linear; 2–3 mm long. Companion sterile spikelet glumes herbaceous; glandular (along midline); winged on margins; distinctly veined; glabrous; attenuate; muticous. Companion sterile spikelet lemmas 2; enclosed by glumes.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets linear; subterete; 10–11 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus linear; 4 mm long; bearded; base pungent; attached obliquely. Spikelet callus hairs red.

GLUMES Glumes dissimilar; with lower wider than upper; exceeding apex of florets; firmer than fertile lemma. Lower glume elliptic, or oblong; 1 length of spikelet; coriaceous; dark brown; without keels; 7–9 -veined. Lower glume surface hispidulous. Lower glume apex obtuse. Upper glume linear; coriaceous; without keels. Upper glume muticous.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret linear; 2.5 mm long; hyaline; 0 -veined; without midvein; without lateral veins. Fertile lemma linear; 6–10 mm long; membranous; 1 -veined. Lemma apex entire; awned; 1 -awned. Principal lemma awn apical; geniculate; 70–120 mm long overall; with twisted column. Column of lemma awn pubescent. Palea fused below to rhachilla internode; 0.2–0.3 length of lemma.

FLOWER Anthers 3; 1 mm long. Stigmas 2.

DISTRIBUTION Africa: west tropical, west-central tropical, northeast tropical, east tropical, southern tropical, south, and western Indian ocean. Asia-temperate: Arabia and China. Asia-tropical: India. North America: southwest USA, southeast USA, and Mexico. South America: Mesoamericana, Caribbean, northern South America, western South America, Brazil, and southern South America.

NOTES Andropogoneae. FTEA.

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