Oropetium thomaeum

HABIT Annual; caespitose. Butt sheaths persistent and investing base of culm; with fibrous dead sheaths. Culms erect; 3–5 cm long. Ligule a ciliolate membrane. Leaf-blades filiform; flat, or conduplicate, or convolute; 1.5–3 cm long; 0.3–0.8 mm wide; stiff. Leaf-blade apex obtuse, or acute.

INFLORESCENCE Inflorescence composed of racemes; embraced at base by subtending leaf.

Racemes 1; single; sinuous; smoothly terete; bilateral; 1–4 cm long. Rhachis tough; subcylindrical and excavated; 0.5–1 mm wide. Spikelet packing adaxial; regular; 2 -rowed.

Spikelets sunken; solitary. Fertile spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; dorsally compressed; (1.8–)2–2.5 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus pubescent.

GLUMES Glumes deciduous; dissimilar; exceeding apex of florets; firmer than fertile lemma; parallel to lemmas, or recurved at apex. Lower glume oblong; 0.4 mm long; 0.2 length of upper glume; hyaline; without keels; 0 -veined. Lower glume lateral veins absent. Lower glume apex truncate, or acute. Upper glume lanceolate; (1.8–)2–2.5 mm long; 2.5–3 length of adjacent fertile lemma; herbaceous; without keels; 3 -veined. Upper glume apex acute.

FLORETS Fertile lemma obovate; 0.7–1 mm long; membranous; without keel; 1(–3) -veined. Lemma apex dentate; 2 -fid; mucronate. Palea hyaline; 2 -veined.

FRUIT Caryopsis with tardily free pericarp; obovoid; 0.5–0.8 mm long.

DISTRIBUTION Africa: northeast tropical and east tropical. Asia-temperate: Arabia. Asia-tropical: India and Indo-China.

NOTES Eragrostideae. FTEA.

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