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.

Ischaemum ritchiei

HABIT Annual. Culms geniculately ascending, or decumbent; 40–80 cm long; rooting from lower nodes. Ligule an eciliate membrane; 8 mm long; lacerate. Leaf-blade base sagittate; with a false petiole; petiole 4–8 cm long. Leaf-blades linear, or elliptic; 10–20 cm long; 10–20 mm wide; flaccid. Leaf-blade margins smooth, or scaberulous. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 2; paired; 3–4 cm long. Rhachis fragile at the nodes; semiterete; ciliate on margins. Rhachis internodes inflated; 6 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 oblong; 0.5 mm long; 0.1 length of fertile spikelet.

STERILE SPIKELETS Basal sterile spikelets well-developed; 6 in number (3 pairs); sessile and pedicelled; male; 8 mm long. Basal sterile spikelet glumes rugose; glabrous; lemmas awnless.

Companion sterile spikelets well-developed; male; lanceolate; laterally compressed; 6 mm long; as long as fertile; separately deciduous. Companion sterile spikelet glumes chartaceous; keeled. Companion sterile spikelet lemmas 2; enclosed by glumes; entire; muticous.

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

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume oblong; 1 length of spikelet; coriaceous; 2-keeled; keeled all along; keeled laterally. Lower glume surface muricate, or rugose; rough on flanks; pilose; hairy below. Lower glume apex acute. Upper glume lanceolate; coriaceous; much thinner above; 1-keeled; 3 -veined. Upper glume surface scabrous.

FLORETS Basal sterile florets male; with palea. Lemma of lower sterile floret lanceolate, or oblong; hyaline; 3 -veined. Fertile lemma oblong; 4.5 mm long; hyaline; without keel; 3 -veined. Lemma apex lobed; 2 -fid; incised 0.5 of lemma length; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 9–10 mm long overall; with twisted column. Column of lemma awn glabrous. Palea 1 length of lemma.

FLOWER Anthers 3; 3 mm long.

DISTRIBUTION Asia-tropical: India.

NOTES Andropogoneae. Bor 1993.

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