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.

Opizia

HABIT Annual (1), or perennial (1). Stolons absent (1), or present (1). Culms slender (1/1); 4–12.25–25 cm long. Ligule a ciliolate membrane. Leaf-blades linear, or triangular (1).

INFLORESCENCE Monoecious, or dioecious (1). Inflorescence composed of racemes; embraced at base by subtending leaf.

Racemes single, or borne along a central axis (1); unilateral; bearing 1–4 fertile spikelets on each (1/1). Rhachis deciduous from axis (1/1); angular; terminating in a spikelet (1), or barren extension (1); extension subulate (1/1). Spikelet packing lax.

Spikelets solitary. Fertile spikelets sessile. Male spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; with diminished florets at the apex. Spikelets lanceolate (1), or cuneate (1); laterally compressed; 1.66–2.64–3.5 mm long; falling entire. Spikelet callus brief (1), or square (1); pubescent (1/1).

GLUMES Glumes one the lower absent or obscure (1), or two (1); reaching apex of florets; thinner than fertile lemma. Lower glume lanceolate (1/1); 0.5 length of upper glume; hyaline (1/1). Lower glume surface without pits (1/1). Lower glume apex acute (1/1). Upper glume lanceolate (1), or oblong (1); 1 length of adjacent fertile lemma; membranous; without keels; 1 -veined. Upper glume surface pilose. Upper glume apex obtuse (1), or acute (1).

FLORETS Fertile florets female. Fertile lemma ovate; coriaceous; much thinner above; keeled; wingless; 3 -veined. Lemma lateral veins prominent (1/1). Lemma surface unwrinkled; without grooves; glabrous (1), or pilose (1). Lemma apex entire (1), or lobed (1); 3 -fid (1/1); obtuse (1/1); muticous (1), or awned (1); 3 -awned (1/1). Principal lemma awn from a sinus (1/1). Lateral lemma awns subequal to principal (1/1). Palea 1 length of lemma; cartilaginous; 2 -veined. Palea keels wingless (1), or winged (1). Apical sterile florets 1 in number; lanceolate. Apical sterile lemmas awned.

MALE Male inflorescence terminal; unlike female; a single raceme (1), or of racemes along a central axis; with pectinate racemes. Male spikelets distinct from female; lanceolate. Male spikelet glumes 2. Male spikelet lemma muticous.

DISTRIBUTION North America, or South America (1).

Please cite this publication as detailed in How to Cite Version: 27th January 2014.