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.

Hymenachne pernambucensis

HABIT Perennial. Rhizomes elongated. Culms robust; 200–300 cm long; 8–10 mm diam. Culm-internodes 8–22 cm long; distally glabrous, or pilose. Culm-nodes black; glabrous, or pubescent. Lateral branches ample; arising from mid culm and upper culm. Leaf-sheaths 8.7–18 cm long; glabrous on surface, or pilose; with tubercle-based hairs. Ligule an eciliate membrane; 0.5–1.3 mm long. Collar dark. Leaf-blade base broadly rounded. Leaf-blades lanceolate; 17–60 cm long; 8–20 mm wide. Leaf-blade midrib conspicuous. Leaf-blade surface glabrous, or pilose; sparsely hairy. Leaf-blade margins scaberulous. Leaf-blade apex attenuate.

INFLORESCENCE Inflorescence a panicle.

Panicle open; lanceolate, or elliptic; 27–40 cm long; 8–12 cm wide; contracted about secondary branches. Primary panicle branches ascending. Panicle axis scabrous; glabrous to pubescent. Panicle branches pubescent in axils.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels 0.4–2 mm long; scabrous.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; dorsally compressed; acute; 1.7–2.2 mm long; 0.4–0.8 mm wide; falling entire.

GLUMES Glumes dissimilar; reaching apex of florets; thinner than fertile lemma. Lower glume ovate; 0.8–1.2 mm long; 0.5 length of spikelet; membranous; without keels; 3 -veined. Lower glume primary vein scabrous. Lower glume apex acute. Upper glume elliptic; 1.4–2.1 mm long; 0.8–0.9 length of spikelet; membranous; without keels; 3–5 -veined. Upper glume primary vein scabrous. Upper glume apex acute.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret similar to upper glume; oblong; 1 length of spikelet; membranous; 3–5 -veined; scabrous; rough on midvein; acute. Fertile lemma elliptic; dorsally compressed; 1.7–2.2 mm long; 0.4–0.8 mm wide; chartaceous; without keel. Lemma margins involute. Lemma apex acute; scabrous. Palea embraced by lemma; involute; chartaceous.

FRUIT Caryopsis ellipsoid; 0.9–1 mm long.

DISTRIBUTION South America: Brazil and southern South America.

NOTES Paniceae. Zuloaga 1994.

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