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 muticum

HABIT Perennial; mat forming. Stolons present. Culms prostrate, or rambling; 15–40 cm long; 2–6 mm diam.; rooting from lower nodes. Leaf-sheaths outer margin hairy. Leaf-sheath auricles erect. Ligule an eciliate membrane; 1 mm long. Leaf-blade base cordate. Leaf-blades 2–15 cm long; 4–14 mm wide. Leaf-blade apex acute, or acuminate.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 2; paired; appressed back to back; 1.5–4.5 cm long. Rhachis fragile at the nodes; angular; ciliate on margins. Rhachis internodes columnar; 5 mm long; flat and forming a U or V shape with the pedicel in rear view. Rhachis internode tip transverse; cupuliform.

Spikelets in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels columnar; 5 mm long; ciliate.

STERILE SPIKELETS Companion sterile spikelets well-developed; containing empty lemmas, or male; ovate; 6.2–6.6 mm long; as long as fertile; separately deciduous. Companion sterile spikelet glumes chartaceous; keeled; winged on keels; acute, or acuminate; muticous. Companion sterile spikelet lemmas 2; enclosed by glumes; muticous.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets ovate; dorsally compressed; acute; 5–8 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus glabrous; base truncate; inserted.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume ovate; 1 length of spikelet; coriaceous; pallid; 2-keeled; keeled above; keeled laterally; winged on keel; winged narrowly; winged above; 6–8 -veined. Lower glume surface convex. Upper glume lanceolate; coriaceous; 1-keeled; keeled above; winged on keel; winged above; 3–5 -veined. Upper glume margins ciliate. Upper glume apex acute.

FLORETS Basal sterile florets male; with palea. Lemma of lower sterile floret ovate; 5.8 mm long; 0.9 length of spikelet; membranous; 3 -veined; ciliate on margins; acute. Fertile lemma ovate; 5.4 mm long; membranous; without keel; 3 -veined. Lemma margins ciliate. Lemma apex lobed; 2 -fid; muticous, or mucronate, or awned; 1 -awned. Principal lemma awn from a sinus; 1–3 mm long overall; not or scarcely exserted from spikelet. Palea 1 length of lemma.

FLOWER Anthers 3; 2.6 mm long. Stigmas white.

DISTRIBUTION Asia-temperate: eastern Asia. Asia-tropical: India, Indo-China, Malesia, and Papuasia. Australasia: Australia. Pacific: southwestern and northwestern.

NOTES Andropogoneae. Gilliland.

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