Sorghastrum pogonostachyum

HABIT Perennial; caespitose. Rhizomes short. Culms 45–120 cm long. Ligule an eciliate membrane. Leaf-blades convolute; 9–15 cm long; 1.5–2 mm wide.

INFLORESCENCE Inflorescence a panicle with branches tipped by a raceme.

Panicle open; linear; 6–15 cm long. Primary panicle branches 4–8 in number; simple.

Racemes 4–7 cm long; bearing few fertile spikelets; bearing 3–7 fertile spikelets on each. Rhachis fragile at the nodes; ciliate on margins. Spikelet packing lax. Rhachis internodes filiform.

Spikelets in pairs. Fertile spikelets sessile, or sessile and pedicelled; 1 in the cluster, or 2 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster, or 0 in the cluster. Pedicels filiform; ciliate.

STERILE SPIKELETS Companion sterile spikelets represented by barren pedicels.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; dorsally compressed; 5–6.5 mm long; falling entire; deciduous with accessory branch structures, or from the base. Spikelet callus bearded; base obtuse. Spikelet callus hairs white; 0.33–0.75 length of spikelet.

GLUMES Glumes dissimilar; firmer than fertile lemma. Lower glume oblong; 1 length of spikelet; coriaceous; dark brown; without keels; 9 -veined. Lower glume surface pilose. Lower glume apex truncate. Upper glume oblong; without keels.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret oblong; 1 length of spikelet; hyaline; 2 -veined; ciliate on margins. Fertile lemma oblong; hyaline; without keel. Lemma margins ciliolate. Lemma apex entire; muticous, or awned; 1 -awned. Principal lemma awn apical; straight; 3–6 mm long overall; without a column. Palea absent or minute.

FLOWER Lodicules 2; glabrous.

DISTRIBUTION Africa: east tropical and southern tropical.

NOTES Andropogoneae. FTEA.

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