Heteropogon contortus

HABIT Perennial; caespitose. Basal innovations intravaginal. Culms erect; 30–100 cm long; 1.5–3 mm diam. Culm-internodes solid. Culm-nodes black. Lateral branches fastigiate. Leaves cauline. Leaf-sheaths keeled. Ligule a fringe of hairs; 1 mm long. Collar glabrous, or pilose. Leaf-blades 3–30 cm long; 2–8 mm wide. Leaf-blade surface ribbed. Leaf-blade apex abruptly acute.

INFLORESCENCE Inflorescence composed of racemes. Peduncle antrorsely scabrous above.

Racemes 1; single; erect; unilateral; 3–10 cm long. Rhachis fragile at the nodes; glabrous on margins. Rhachis internodes linear. 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; 6–34 in number; larger than fertile. Basal sterile spikelet glumes smooth on margins; lower glume muticous.

Companion sterile spikelets well-developed; male; lanceolate; asymmetrical; dorsally compressed; 5–15 mm long; longer than fertile; separately deciduous. Companion sterile spikelet callus linear; 2–3 mm long. Companion sterile spikelet glumes chartaceous; eglandular; winged on margins; distinctly veined; smooth, or tuberculate; glabrous, or pubescent, or pilose, or villous; acute; 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; 5.5–10 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus linear; 2–3 mm long; bearded; base pungent; attached obliquely. Spikelet callus hairs red; 0.2 length of spikelet.

GLUMES Glumes dissimilar; with lower wider than upper; exceeding apex of florets; firmer than fertile lemma. Lower glume linear; 1 length of spikelet; coriaceous; dark brown; without keels; 9 -veined. Lower glume surface puberulous, or pubescent, or pilose. 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; 1 length of fertile lemma; hyaline; 2 -veined; erose. Fertile lemma linear; 3–5 mm long; membranous; 1 -veined. Lemma apex entire; awned; 1 -awned. Principal lemma awn apical; geniculate; 50–80 mm long overall; with twisted column. Column of lemma awn hirtellous. Palea absent or minute.

FLOWER Anthers 3; 2.5 mm long. Stigmas 2.

DISTRIBUTION Europe: central, southwestern, and southeastern. Africa: north, Macaronesia, west tropical, west-central tropical, northeast tropical, east tropical, southern tropical, south, middle Atlantic ocean, and western Indian ocean. Asia-temperate: western Asia, Arabia, China, and eastern Asia. Asia-tropical: India, Indo-China, Malesia, and Papuasia. Australasia: Australia. Pacific: southwestern, south-central, northwestern, and north-central. North America: southwest USA, south-central 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.