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.

Ischaemum fragile

HABIT Perennial. Culms erect, or geniculately ascending; 40–110 cm long; 3–7 -noded. Culm-nodes glabrous, or bearded. Leaf-sheaths keeled; glabrous on surface, or pilose. Ligule an eciliate membrane; 2–3 mm long. Leaf-blades 10–20 cm long; 3–7 mm wide. Leaf-blade surface glabrous, or pubescent. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 1; single; 4–6 cm long. Rhachis fragile at the nodes; angular; ciliate on margins. Rhachis internodes inflated; 3.5–4 mm long. Rhachis internode tip transverse; cupuliform.

Spikelets in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels inflated; 3.5–4 mm long; 1 length of internode; ciliate.

STERILE SPIKELETS Companion sterile spikelets well-developed; comprising 2 subequal glumes without lemmas, or containing empty lemmas; lanceolate; laterally compressed; 2–4 mm long; shorter than fertile; separately deciduous. Companion sterile spikelet glumes chartaceous; keeled. Companion sterile spikelet lemmas 2; enclosed by glumes; muticous.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets oblong; dorsally compressed; 5–6 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus pubescent; base truncate; inserted.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma; shiny. Lower glume oblong; 1 length of spikelet; coriaceous; much thinner above; 2-keeled; keeled above; keeled laterally; winged on keel; winged narrowly; winged above. Lower glume surface convex. Lower glume apex emarginate. Upper glume lanceolate; coriaceous; 1-keeled; winged on keel. Upper glume awned; 1 -awned. Upper glume awn 1–3 mm long.

FLORETS Basal sterile florets male; with palea. Lemma of lower sterile floret lanceolate; membranous; 3 -veined. Fertile lemma oblong; membranous; without keel. Lemma apex lobed; 2 -fid; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 10–18 mm long overall; with twisted column. Column of lemma awn glabrous.

FLOWER Anthers 3.

DISTRIBUTION Asia-tropical: Papuasia. Australasia: Australia.

NOTES Andropogoneae. Reeder 1993.

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