Isachne longifolia

HABIT Perennial. Culms prostrate; 60–100 cm long. Culm-internodes terete. Lateral branches ample. Leaves cauline. Leaf-sheaths striately veined; smooth; glabrous on surface. Ligule a fringe of hairs; 0.5 mm long. Leaf-blades linear, or lanceolate; 8–16(–21) cm long; 6–10(–15) mm wide; coriaceous. Leaf-blade surface smooth; glabrous. Leaf-blade apex acuminate, or attenuate.

INFLORESCENCE Inflorescence a panicle.

Panicle open; oblong; 10–20 cm long. Primary panicle branches appressed, or ascending; 2–8 cm long. Panicle branches smooth.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels filiform; 0.5–2 mm long.

FERTILE SPIKELETS Spikelets comprising 2 fertile florets; without rhachilla extension. Spikelets elliptic, or oblong; dorsally compressed; 1.5–2 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes suppressed between florets.

GLUMES Glumes deciduous; similar; reaching apex of florets; thinner than fertile lemma. Lower glume elliptic; 1.5–2 mm long; 1 length of upper glume; 1 length of spikelet; membranous; without keels; 5–9 -veined. Lower glume apex obtuse, or acute. Upper glume elliptic; 1.5–2 mm long; membranous; without keels; 5–9 -veined. Upper glume apex obtuse, or acute.

FLORETS Fertile florets all alike. Fertile lemma oblong; 1.5 mm long; coriaceous; without keel; 5–7 -veined. Lemma lateral veins obscure. Lemma surface glabrous. Lemma margins involute; interlocking with palea keels. Lemma apex obtuse. Palea coriaceous.

DISTRIBUTION Africa: western Indian ocean.

NOTES Isachneae. SAR 2011.

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