Isachne humbertiana

HABIT Perennial. Culms erect, or geniculately ascending; 40–50 cm long. Culm-internodes striate; smooth; distally glabrous. Lateral branches sparse. Leaf-sheaths loose; mostly shorter than adjacent culm internode; outer margin hairy. Ligule a fringe of hairs. Leaf-blades lanceolate; 7–9 cm long; 5–6 mm wide; coriaceous. Leaf-blade venation prominent; with 6 secondary veins. Leaf-blade surface pilose; hairy adaxially. Leaf-blade margins cartilaginous; scaberulous. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence a panicle.

Panicle open; ovate; 4.5–5.5 cm long; 3–3.5 cm wide. Primary panicle branches spreading; 1 -nate.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels filiform; 1–2.5 mm long.

FERTILE SPIKELETS Spikelets comprising 2 fertile florets; without rhachilla extension. Spikelets elliptic; dorsally compressed; 2 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes 0.75–0.9 mm long.

GLUMES Glumes deciduous; similar; shorter than spikelet; thinner than fertile lemma. Lower glume lanceolate, or oblong; 1.7–1.8 mm long; 0.9 length of spikelet; membranous; without keels; 5 -veined. Lower glume lateral veins obscure. Lower glume surface pubescent; hairy at apex. Lower glume apex acuminate. Upper glume ovate; 1.7–1.8 mm long; 0.9 length of spikelet; membranous; without keels; 5 -veined. Upper glume lateral veins obscure. Upper glume surface puberulous; hairy at apex. Upper glume apex obtuse.

FLORETS Fertile florets with the lowest dissimilar. Lowest fertile lemma bisexual; elliptic; 1.9–2 mm long. Fertile lemma elliptic; 1.3–1.4 mm long; coriaceous; without keel. Lemma margins involute. Lemma apex obtuse. Palea coriaceous.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION Africa: western Indian ocean.

NOTES Isachneae. Camus 2007.

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