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.

Dichanthium oliganthum

HABIT Annual. Culms geniculately ascending, or decumbent; weak; 10–30 cm long; rooting from lower nodes. Ligule an eciliate membrane; 1.5 mm long. Leaf-blades 5–7.5 cm long; 2–3 mm wide. Leaf-blade midrib widened. Leaf-blade surface pilose; hairy on both sides; with tubercle-based hairs. Leaf-blade margins cartilaginous; scabrous. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence composed of racemes. Peduncle hirsute above; widened at apex.

Racemes 1(–2); single; 2–3.5 cm long. Rhachis fragile at the nodes; flattened; ciliate on margins. Rhachis hairs white. Rhachis internodes linear; 2 mm long.

Spikelets in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels linear; flattened; 2.25 mm long; without a translucent median line; ciliate.

STERILE SPIKELETS Basal sterile spikelets well-developed; 6 in number; sessile and pedicelled; barren; elliptic; 4–5 mm long; larger than fertile. Basal sterile spikelet glumes chartaceous; glabrous, or pilose (at tip); lemmas awnless.

Companion sterile spikelets well-developed; containing empty lemmas; elliptic; 4–5.5 mm long; as long as fertile; separately deciduous. Companion sterile spikelet glumes chartaceous; 9–11 -veined; pilose (above); truncate. Companion sterile spikelet lemmas enclosed by glumes; muticous.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets oblong; dorsally compressed; truncate; 4–5 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus pilose; base obtuse; attached transversely.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume oblong; 3.5 mm long; 0.9 length of spikelet; chartaceous; without keels; keel-less except near apex; 6 -veined. Lower glume surface convex, or flat; pubescent. Lower glume margins ciliate. Lower glume apex truncate. Upper glume lanceolate; chartaceous; 1-keeled.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret elliptic; 2.5–3 mm long; hyaline; 0 -veined; without midvein; without lateral veins. Fertile lemma linear; 1.5 mm long; hyaline; without keel; 1 -veined. Lemma apex entire; awned; 1 -awned. Principal lemma awn apical; geniculate; 30–35 mm long overall; with twisted column. Column of lemma awn puberulous; hairy on the spiral. Palea absent or minute.

FLOWER Anthers 3; 1 mm long.

FRUIT Caryopsis with adherent pericarp; obovoid; 2 mm long. Embryo 0.5 length of caryopsis. Hilum punctiform.

DISTRIBUTION Asia-tropical: India.

NOTES Andropogoneae. Bor.

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