Hyperthelia polychaeta

HABIT Annual. Culms 150–200 cm long; 2–4 mm diam. Leaf-sheaths glabrous on surface. Leaf-sheath auricles erect; 3–6 mm long. Ligule an eciliate membrane; 3–6 mm long; scarious; truncate. Leaf-blades 20–40 cm long; 2–4 mm wide. Leaf-blade surface glabrous, or pilose; sparsely hairy.

INFLORESCENCE Synflorescence compound; scanty; 30 cm long. Inflorescence composed of racemes; terminal and axillary; subtended by a spatheole; exserted. Spatheole linear; 6–10 cm long; scarious; glabrous. Peduncle 7–12 cm long; pilose above.

Racemes 2; paired; erect; 3–6 cm long; bearing few fertile spikelets; bearing 2–5 fertile spikelets on each. Rhachis fragile at the nodes; ciliate on margins. Rhachis internodes filiform. Rhachis internode tip oblique; flat. Raceme-bases filiform; subequal, or unequal (the longer measured); 2–4 mm long; glabrous, or pilose; extended into an oblong appendage; with 3–4 mm long appendage.

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

STERILE SPIKELETS Basal sterile spikelets well-developed; lower raceme 2 in number; 0 in upper raceme; male; lanceolate; 12–15 mm long; equalling fertile. Basal sterile spikelet glumes glabrous; lower glume muticous.

Companion sterile spikelets well-developed; male; lanceolate; 14–16 mm long; longer than fertile; deciduous with the fertile. Companion sterile spikelet callus indistinct; acute. Companion sterile spikelet glumes coriaceous; acuminate; muticous, or awned; one glume awned; with 1–2 mm long awn. 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; 12 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus cuneate; 2 mm long; pilose; base pungent; 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. Upper glume oblong; coriaceous; without keels; 3 -veined. Upper glume apex setaceously attenuate; muticous, or mucronate.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret oblong; hyaline; 2 -veined; ciliate on margins. Fertile lemma linear; 5 mm long; hyaline; without keel; 3 -veined. Lemma margins ciliate. Lemma apex dentate; 2 -fid; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 50–70 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.