GrassBase - The Online World Grass Flora

Descriptions

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

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

Panicum stevensianum

HABIT Perennial. Culms prostrate; 30–60 cm long; rooting from lower nodes. Culm-internodes elliptical in section; distally glabrous. Culm-nodes brown; glabrous. Leaf-sheaths striately veined; glabrous on surface, or pilose; with tubercle-based hairs; outer margin hairy. Ligule a ciliolate membrane; 0.4–1 mm long. Collar glabrous. Leaf-blades 2–8 mm wide. Leaf-blade surface glabrous. Leaf-blade margins ciliate; hairy at base. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence a panicle.

Panicle open, or contracted; linear, or lanceolate; 8–28 cm long; 1–6 cm wide; contracted about primary branches. Primary panicle branches appressed; 1.5–3 cm long; bearing spikelets almost to the base. Panicle axis scabrous. Panicle branches scabrous.

Spikelets in pairs. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; dorsally compressed; acute; 2 mm long; 0.8 mm wide; falling entire.

GLUMES Glumes dissimilar; reaching apex of florets; thinner than fertile lemma; gaping. Lower glume ovate; 0.8–1.1 mm long; 0.25 length of spikelet; membranous; without keels; 3 -veined. Lower glume apex acuminate. Upper glume ovate; 1 length of spikelet; membranous; 1-keeled; 3–5 -veined. Upper glume primary vein scaberulous. Upper glume apex acute.

FLORETS Basal sterile florets male; with palea. Lemma of lower sterile floret similar to upper glume; ovate; 1 length of spikelet; membranous; 3–5 -veined; acute. Palea of lower sterile floret 1 length of lemma. Fertile lemma elliptic; dorsally compressed; 1.9 mm long; 0.6 mm wide; indurate; pallid; without keel. Lemma margins involute. Lemma apex acute; scabrous. Palea involute; indurate.

FLOWER Anthers 3; 1.2 mm long.

DISTRIBUTION South America: Caribbean.

NOTES Paniceae. Chase 1994.

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