GrassBase - The Online World Grass Flora


W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Sorghastrum pohlianum

HABIT Perennial; caespitose. Rhizomes elongated; scaly. Culms erect; 90–160 cm long; 2–3.5 mm diam. Culm-internodes hollow; smooth; distally glabrous. Culm-nodes brown; pubescent. Leaf-sheaths 14–23 cm long; glabrous on surface. Leaf-sheath auricles erect; 3–4.6 mm long. Ligule an eciliate membrane; 2.5–3.5 mm long. Leaf-blades 16–30 cm long; 3.8–7 mm wide. Leaf-blade margins smooth, or scaberulous. Leaf-blade apex acute.

INFLORESCENCE Inflorescence a panicle with branches tipped by a raceme. Peduncle 34–40 cm long.

Panicle open; pyramidal; 16–20 cm long. Primary panicle branches 3.3–5.9 cm long. Panicle branches capillary.

Racemes bearing a triad of spikelets, or few fertile spikelets. Rhachis fragile at the nodes. Rhachis internodes filiform.

Spikelets in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels filiform; 4–4.5 mm long; villous.

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; 5.9–6.5 mm long; 1–1.2 mm wide; falling entire; deciduous with accessory branch structures. Spikelet callus bearded; base obtuse.

GLUMES Glumes dissimilar; firmer than fertile lemma. Lower glume lanceolate; 5–5.8 mm long; 1 length of spikelet; chartaceous, or coriaceous; light brown; without keels. Lower glume lateral veins distinct. Lower glume surface pilose. Lower glume apex truncate. Upper glume lanceolate; 5.9–6 mm long; 1 length of spikelet; chartaceous, or coriaceous; 1-keeled; 5 -veined. Upper glume apex acute.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret oblong; 2.2–4.6 mm long; hyaline; 2 -veined; ciliate on margins; dentate; 2 -fid. Fertile lemma oblong; 2.4–4.4 mm long; 1–1.3 mm wide; hyaline; without keel. Lemma apex lobed; 2 -fid; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 25–30 mm long overall; with twisted column. Palea absent or minute.

FLOWER Anthers 3; 2.2–2.5 mm long; yellow.

DISTRIBUTION North America: Mexico.

NOTES Andropogoneae. Davila 2004.

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