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.

Oryzopsis

HABIT Perennial. Rhizomes absent (7), or short (1). Culms erect (7), or geniculately ascending (1), or prostrate (1); 10–38.12–90 cm long. Lateral branches lacking (1/1). Ligule an eciliate membrane (7), or a ciliolate membrane (1). Leaf-blades filiform (3), or linear (5); herbaceous (7), or coriaceous (1); stiff (1), or firm (7).

INFLORESCENCE Inflorescence a panicle; exserted, or embraced at base by subtending leaf (2).

Panicle open (4), or contracted (4).

Spikelets appressed (1/1); solitary. Fertile spikelets pedicelled. Pedicels filiform (1/1).

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets elliptic (2), or oblong (2), or ovate (4); dorsally compressed; 3.5–5.75–8 mm long; breaking up at maturity; disarticulating below each fertile floret. Spikelet callus pubescent (1/1). Floret callus brief (5), or evident (3); pubescent (3/6), or pilose (3/6).

GLUMES Glumes persistent; shorter than spikelet (1), or reaching apex of florets (4), or exceeding apex of florets (3); thinner than fertile lemma; parallel to lemmas (7), or gaping (1). Lower glume oblong (3), or ovate (5); 0.9–1.012–1.2 length of upper glume; hyaline (1), or membranous (7); without keels; 3 -veined (4), or 4 -veined (2), or 5 -veined (4), or 7 -veined (2). Lower glume lateral veins obscure (2), or distinct (5), or prominent (1). Lower glume surface without pits; glabrous (7), or puberulous (3). Lower glume apex truncate (1), or obtuse (1), or acute (3), or acuminate (3), or attenuate (1). Upper glume oblong (3), or ovate (5); 0.9–1.268–2 length of adjacent fertile lemma; hyaline (1), or membranous (7); without keels; 3 -veined (4), or 4 -veined (2), or 5 -veined (4), or 7 -veined (2). Upper glume surface glabrous (7), or puberulous (3). Upper glume apex truncate (1), or obtuse (1), or acute (3), or acuminate (3), or attenuate (1).

FLORETS Fertile lemma elliptic (1), or oblong (3), or ovate (4); dorsally compressed; coriaceous; without keel; wingless; 5 -veined (3/3). Lemma surface unwrinkled; without grooves; glabrous (1), or pubescent (5), or hirsute (1), or villous (1); hairy on back (7/7), or on veins (1/7). Lemma margins convolute; covering most of palea. Lemma apex entire (6), or dentate (2); 2 -fid (2/2); obtuse (3/5), or acute (2/5); muticous (1), or awned; 1 -awned. Principal lemma awn apical (6), or from a sinus (2); straight (5), or curved (1), or flexuous (1), or geniculate (1). Palea 1 length of lemma; membranous (1), or coriaceous (7); 2 -veined; without keels.

FLOWER Lodicules 2 (1/2), or 3 (1/2). Anthers 3 (2/2).

FRUIT Caryopsis apex rostrate (6/6).

DISTRIBUTION Temperate Asia (1), or North America.

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