Isachne rigidifolia

HABIT Perennial. Stolons present. Culms rambling; 15–40 cm long. Lateral branches ample. Leaves distichous. Leaf-sheaths longer than adjacent culm internode; glabrous on surface; outer margin hairy. Ligule a ciliate membrane. Leaf-blades lanceolate; 2–4 cm long; 2–4 mm wide; coriaceous; stiff. Leaf-blade midrib conspicuous. Leaf-blade margins cartilaginous. Leaf-blade apex pungent.

INFLORESCENCE Inflorescence a panicle.

Panicle open; oblong; 2–5 cm long. Primary panicle branches ascending, or spreading. Panicle branches stiff.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels 1–2 mm long.

FERTILE SPIKELETS Spikelets comprising 2 fertile florets; without rhachilla extension. Spikelets orbicular; tilted on the pedicel; dorsally compressed; 2 mm long; breaking up at maturity; disarticulating above glumes but not between florets.

GLUMES Glumes deciduous; similar; shorter than spikelet; thinner than fertile lemma. Lower glume oblong; 0.9 length of spikelet; membranous; without keels; 5 -veined. Lower glume surface glabrous, or pubescent; hairy above. Lower glume apex obtuse. Upper glume orbicular; 0.9 length of spikelet; membranous; without keels; 5 -veined. Upper glume surface glabrous, or puberulous; hairy above. Upper glume apex obtuse.

FLORETS Fertile lemma orbicular; 2 mm long; coriaceous; without keel. Lemma margins involute. Lemma apex obtuse. Palea coriaceous; 2 -veined.

FLOWER Anthers 3.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION South America: Caribbean.

NOTES Isachneae. N Amer Fl 1994.

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