Parahyparrhenia annua

HABIT Annual; caespitose. Culms erect; 30–160 cm long. Leaf-sheath auricles erect; 2–5 mm long. Ligule an eciliate membrane; 2–5 mm long. Leaf-blades 5–45 cm long; 1–6 mm wide.

INFLORESCENCE Inflorescence composed of racemes; subtended by a spatheole. Spatheole linear; 6–15 cm long; herbaceous.

Racemes (1–)2; paired; 2–6 cm long; bearing few fertile spikelets; bearing 4–7 fertile spikelets on each. Rhachis fragile at the nodes; ciliate on margins. Rhachis internodes filiform. Rhachis internode tip oblique; flat. Raceme-bases filiform; unequal (the longer measured); 3–6 mm long; glabrous.

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

STERILE SPIKELETS Basal sterile spikelets well-developed; 2 in number (lower raceme); 0 in upper raceme; barren; smaller than fertile. Basal sterile spikelet lower glume muticous; lemmas awnless.

Companion sterile spikelets well-developed; comprising 2 subequal glumes without lemmas, or containing empty lemmas, or male; lanceolate; 5–11 mm long; as long as fertile; separately deciduous. Companion sterile spikelet callus indistinct, or oblong (0–0.5 mm); obtuse. Companion sterile spikelet glumes coriaceous; awned; with 1–9 mm long awn.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets linear; subterete; 5–12 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus cuneate; 1–4 mm long; pilose; base pungent; attached obliquely. Spikelet callus hairs white, or red.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume oblong; 1 length of spikelet; coriaceous; without keels. Lower glume surface with a longitudinal median groove. Upper glume oblong; coriaceous. Upper glume muticous, or awned. Upper glume awn 0–10 mm long.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret oblong; hyaline; 2 -veined; ciliolate on margins. Fertile lemma oblong; 4 mm long; hyaline; without keel; 3 -veined. Lemma margins ciliolate; hairy above. Lemma apex dentate; 2 -fid; incised 0.1 of lemma length; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 35–100 mm long overall; with twisted column. Column of lemma awn pubescent. Palea absent or minute.

DISTRIBUTION Africa: west tropical, west-central tropical, and northeast tropical.

NOTES Andropogoneae. WDC.

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