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 leptachne

HABIT Perennial. Culms erect. Culm-nodes brown; glabrous, or pubescent. Lateral branches lacking. Leaf-sheaths 11–14 cm long; longer than adjacent culm internode; reticulately veined; glabrous on surface, or puberulous; with tubercle-based hairs. Ligule an eciliate membrane; 0.8–1 mm long; lacerate. Leaf-blade base cordate; with a brief petiole-like connection to sheath; petiole pubescent. Leaf-blades lanceolate; 13–22 cm long; 18–25 mm wide. Leaf-blade surface glabrous. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence composed of racemes. Peduncle 10 cm long.

Racemes numerous; borne along a central axis; unilateral; 1–6 cm long. Central inflorescence axis 25–40 cm long. Rhachis tuberculate on margins; ciliate on margins.

Spikelets in pairs. Fertile spikelets pedicelled. Pedicels oblong; 0.2–0.5 mm long; scabrous.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; dorsally compressed; 2.1–3.2 mm long; 0.5–0.8 mm wide; falling entire.

GLUMES Glumes dissimilar; shorter than spikelet; thinner than fertile lemma. Lower glume ovate; 1–2 mm long; 0.2–0.5 length of spikelet; membranous; 1-keeled; 3(–5) -veined. Lower glume primary vein scabrous. Lower glume apex acute. Upper glume elliptic; 0.8 length of spikelet; membranous; without keels; 5(–7) -veined. Upper glume apex acute.

FLORETS Basal sterile florets male, or barren; with palea, or without significant palea. Lemma of lower sterile floret similar to upper glume; elliptic; 1 length of spikelet; membranous; 1-keeled; 3(–5) -veined; scabrous; rough on midvein; acute. Palea of lower sterile floret 0–0.8 length of lemma. Fertile lemma elliptic; dorsally compressed; 1.8–2.5 mm long; chartaceous; light brown; without keel; 5 -veined. Lemma margins involute. Lemma apex acute; scabrous. Palea involute; chartaceous.

FRUIT Caryopsis obovoid. Embryo 0.33 length of caryopsis. Hilum elliptic.

DISTRIBUTION South America: Brazil.

NOTES Paniceae. Zuloaga 1994.

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