GrassBase - The Online World Grass Flora


W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Isachne surgens

HABIT Perennial. Culms geniculately ascending, or decumbent; 80–100 cm long; 1 mm diam.; rooting from lower nodes. Culm-internodes smooth; distally glabrous. Culm-nodes glabrous. Lateral branches ample. Leaf-sheaths 15–80 cm long; mostly shorter than adjacent culm internode; glabrous on surface; outer margin hairy. Leaf-sheath oral hairs scanty. Ligule absent. Leaf-blades linear, or lanceolate; 6–7 cm long; 5–8 mm wide. Leaf-blade venation with 4–6 secondary veins. Leaf-blade surface scabrous; rough on both sides; glabrous, or puberulous; hairy abaxially. Leaf-blade margins unthickened, or cartilaginous; scaberulous.

INFLORESCENCE Inflorescence a panicle.

Panicle open; ovate; 4–5 cm long. Primary panicle branches spreading; 1 -nate; 1–2 cm long. Panicle branches capillary; flexuous; smooth.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels filiform.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets oblong; dorsally compressed; 1.7 mm long; breaking up at maturity; disarticulating below each fertile floret.

GLUMES Glumes deciduous; similar; shorter than spikelet; thinner than fertile lemma. Lower glume oblong; 1.7 mm long; 1.1 length of upper glume; 1 length of spikelet; membranous; without keels; 7 -veined. Lower glume lateral veins obscure. Lower glume surface glabrous. Lower glume apex obtuse. Upper glume oblong; 1.5 mm long; 0.9 length of spikelet; membranous; without keels; 7 -veined. Upper glume primary vein obscure. Upper glume surface glabrous. Upper glume apex obtuse.

FLORETS Basal sterile florets male; with palea; separately deciduous. Lemma of lower sterile floret oblong; 1.7 mm long; 1.4 length of fertile lemma; 1 length of spikelet; chartaceous; 5 -veined; obscurely veined; glabrous; obtuse. Fertile florets bisexual, or female. Fertile lemma oblong; 1.2 mm long; coriaceous; without keel. Lemma surface puberulous. Lemma margins involute. Lemma apex obtuse. Palea coriaceous; 2 -veined.

FLOWER Anthers 3.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION Asia-tropical: Malesia.

NOTES Isachneae. Jansen 2001.

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