Hyperthelia colobantha

HABIT Annual; caespitose. Culms erect; 200 cm long; 3–4 mm diam. Leaf-sheaths hirsute. Ligule an eciliate membrane; 1–2 mm long. Leaf-blades 20–45 cm long; 2–3 mm wide. Leaf-blade surface pilose; sparsely hairy.

INFLORESCENCE Synflorescence compound; linear; 20 cm long. Inflorescence composed of racemes; terminal and axillary; subtended by a spatheole; enclosed. Spatheole lanceolate; 2.5 cm long; scarious; hirsute. Peduncle 0.2 cm long; pilose above.

Racemes 2; paired; with abortive upper raceme represented by a single sterile spikelet; 1.2 cm long; bearing few fertile spikelets; bearing 1 fertile spikelets on each. Rhachis fragile at the nodes. Rhachis internodes linear. Rhachis internode tip oblique; flat. Raceme-bases filiform; unequal (the longer measured); 6–7 mm long; pilose; extended into an oblong appendage; with 6 mm long appendage.

Spikelets in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels filiform; ciliate; tip rectangular.

STERILE SPIKELETS Basal sterile spikelets well-developed; lower raceme 2 in number; 0 in upper raceme; male; linear; 8 mm long; smaller than fertile. Basal sterile spikelet lower glume muticous.

Companion sterile spikelets well-developed; male; lanceolate; 9 mm long; as long as fertile; deciduous with the fertile. Companion sterile spikelet callus cuneate; 0.5 mm long; acute. Companion sterile spikelet glumes coriaceous; 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; 9 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus cuneate; 2 mm long; pilose; base acute; attached obliquely. Spikelet callus hairs white.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume oblong; 1 length of spikelet; coriaceous; much thinner above; without keels. Lower glume surface with a longitudinal median groove; pubescent; hairy above. Lower glume apex dentate; 2 -fid; setaceously attenuate. Upper glume oblong; coriaceous; without keels; 3 -veined. Upper glume apex acute; mucronate.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret oblong; hyaline; 2 -veined. Fertile lemma linear; 4.5 mm long; hyaline; without keel; 3 -veined. Lemma apex dentate; 2 -fid; incised 0.15 of lemma length; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 80 mm long overall; with twisted column. Column of lemma awn pubescent. Palea absent or minute.

DISTRIBUTION Africa: west-central tropical.

NOTES Andropogoneae. WDC.

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