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 koleostachys

HABIT Perennial; caespitose. Culms erect, or geniculately ascending; 20–60 cm long. Culm-nodes bearded. Lateral branches lacking, or sparse. Leaf-sheaths glabrous on surface, or pilose. Ligule an eciliate membrane; 1–2 mm long. Leaf-blades lanceolate; 3–11 cm long; 3–7 mm wide. Leaf-blade surface glabrous. Leaf-blade apex attenuate; filiform.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 2; paired; unilateral; 2–5 cm long. Rhachis fragile at the nodes; angular; ciliate on margins. Rhachis internodes columnar; 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 oblong; angular; ciliate.

STERILE SPIKELETS Companion sterile spikelets well-developed; containing empty lemmas, or male; elliptic; laterally compressed; as long as fertile; separately deciduous. Companion sterile spikelet glumes chartaceous; villous; acuminate; muticous. Companion sterile spikelet lemmas 2; enclosed by glumes.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets oblong; dorsally compressed; 4.5–5 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus oblong; 1–1.5 mm long; bearded; base obtuse; inserted. Spikelet callus hairs 2–3 mm long.

GLUMES Glumes dissimilar; reaching apex of florets; firmer than fertile lemma. Lower glume oblong; 1 length of spikelet; chartaceous; 2-keeled; winged on keel; winged narrowly; winged above; 8–11 -veined. Lower glume surface flat; asperulous; rough above; pilose; hairy above. Lower glume apex dentate; 2 -fid. Upper glume lanceolate; chartaceous; 1-keeled. Upper glume apex acuminate.

FLORETS Basal sterile florets male; with palea. Lemma of lower sterile floret lanceolate; 1 length of spikelet; membranous. Fertile lemma oblong; 4 mm long; membranous; without keel. Lemma apex lobed; 2 -fid; incised 0.5 of lemma length; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 14–20 mm long overall; with twisted column. Column of lemma awn glabrous. Palea 1 length of lemma.

DISTRIBUTION Africa: western Indian ocean.

NOTES Andropogoneae. Gr Maur.

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