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 roseotomentosum

HABIT Perennial; caespitose. Butt sheaths pubescent. Culms erect; 70–130 cm long; 6–12 -noded. Culm-nodes pubescent. Leaf-sheaths pilose; with tubercle-based hairs. Ligule an eciliate membrane; 0.5 mm long. Leaf-blades 4–15 cm long; 5–8 mm wide. Leaf-blade apex attenuate; filiform.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 1; single; 5–7 cm long. Rhachis fragile at the nodes; subterete; ciliate on margins. Rhachis hairs white, or red, or purple. Rhachis internodes cuneate; 6 mm long. Rhachis internode tip oblique; cupuliform.

Spikelets in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels cuneate; terete; 6 mm long; ciliate.

STERILE SPIKELETS Companion sterile spikelets rudimentary, or well-developed; comprising 2 subequal glumes without lemmas; elliptic; 2–3.5 mm long; shorter than fertile; separately deciduous. Companion sterile spikelet glumes chartaceous; keeled; winged on keels (above); villous; dentate; 3 -fid; muticous.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets oblong; dorsally compressed; 8–10 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus square; pubescent; base obtuse; inserted.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume oblong; 1 length of spikelet; coriaceous; 2-keeled; keeled laterally; winged on keel; winged broadly; winged near apex. Lower glume primary vein ciliate. Lower glume surface convex; villous; hairy below. Lower glume apex dentate; 3 -fid. Upper glume lanceolate; coriaceous; 1-keeled. Upper glume primary vein ciliate. Upper glume surface puberulous. Upper glume margins ciliate. Upper glume apex emarginate.

FLORETS Basal sterile florets barren; with palea. Lemma of lower sterile floret elliptic; 4 mm long; 0.5 length of spikelet; hyaline; 2 -veined; pilose. Palea of lower sterile floret 0.25 length of lemma. Fertile lemma oblong; 3–3.5 mm long; membranous; without keel. Lemma margins ciliate; hairy above. Lemma apex lobed; 2 -fid; incised 0.25 of lemma length; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 20–30 mm long overall; with twisted column. Column of lemma awn glabrous. Palea lanceolate; 0.33 length of lemma; 0 -veined; without keels.

FLOWER Anthers 3.

DISTRIBUTION Africa: southern tropical.

NOTES Andropogoneae. WDC.

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