Sorghastrum stipoides

HABIT Perennial; caespitose. Rhizomes short. Culms 90–200 cm long. Culm-internodes hollow. Ligule an eciliate membrane. Leaf-blades flat, or convolute; 15–50 cm long; 3–7(–12) mm wide; stiff.

INFLORESCENCE Inflorescence a panicle with branches tipped by a raceme.

Panicle open; linear to lanceolate; 15–40 cm long. Primary panicle branches whorled at lower nodes. Panicle branches capillary.

Racemes bearing few fertile spikelets; 1–4 fertile spikelets on each. Rhachis fragile at the nodes; ciliate on margins. Rhachis internodes filiform.

Spikelets in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 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; 4–6(–6.5) mm long; falling entire; deciduous with accessory branch structures. Spikelet callus pilose; base obtuse.

GLUMES Glumes dissimilar; firmer than fertile lemma; shiny. Lower glume oblong; 1 length of spikelet; coriaceous; dark brown; without keels; 9 -veined. Lower glume lateral veins obscure. Lower glume surface glabrous, or 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; 4–6 mm long; hyaline; without keel; 3 -veined. Lemma margins ciliolate. Lemma apex lobed; 2 -fid; incised 0.2 of lemma length; muticous, or awned; 1 -awned. Principal lemma awn from a sinus; straight, or geniculate; (0–)4–13(–25) mm long overall; with twisted column. Column of lemma awn glabrous, or hispidulous. Palea absent or minute.

FLOWER Lodicules 2; glabrous.

DISTRIBUTION Africa: west tropical, west-central tropical, northeast tropical, east tropical, southern tropical, and south. North America: Mexico. South America: Caribbean, northern South America, western South America, Brazil, and southern South America.

NOTES Andropogoneae. FTEA.

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