Sorghastrum tisserantii

HABIT Annual; caespitose. Culms 60 cm long. Ligule a fringe of hairs. Leaf-blades convolute; 15–30 cm long; 1–2 mm wide.

INFLORESCENCE Inflorescence a panicle with branches tipped by a raceme.

Panicle open; lanceolate; 10–14 cm long. Primary panicle branches spreading; simple, or sparsely divided; 0.3–2.5 cm long. Panicle branches capillary; villous; hairy at tip.

Racemes bearing a triad of spikelets. Rhachis obsolete.

Spikelets in threes. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 2 in the cluster. Pedicels filiform; 0.5 length of fertile spikelet; 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; 10–11 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus linear; 3 mm long; pubescent; base pungent.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume oblong; 1 length of spikelet; coriaceous; much thinner above; dark brown; without keels. Lower glume surface pilose. Upper glume oblong; 0.9 length of spikelet; without keels.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret lanceolate; 8 mm long; hyaline; 2 -veined. Fertile lemma oblong; hyaline; without keel. Lemma apex dentate; 2 -fid; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 45–55 mm long overall; with twisted column. Column of lemma awn pubescent; hairy on the spiral. Palea absent or minute.

FLOWER Lodicules 2.

FRUIT Caryopsis with adherent pericarp; oblanceolate; 4 mm long.

DISTRIBUTION Africa: west-central tropical.

NOTES Andropogoneae. WDC.

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