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.

Rhombolytrum

HABIT Perennial. Culms erect (1), or decumbent (2); 40–57.5–70 cm long. Ligule an eciliate membrane.

INFLORESCENCE Inflorescence a panicle.

Panicle contracted.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels linear (2/2).

FERTILE SPIKELETS Spikelets comprising 3 fertile florets (1), or 4 fertile florets (2), or 8–10 fertile florets (1); with diminished florets at the apex. Spikelets lanceolate (1), or oblong (1), or rhomboid (1); laterally compressed; 4.5–6–7 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes definite. Floret callus pubescent (2/2).

GLUMES Glumes persistent; shorter than spikelet; firmer than fertile lemma. Lower glume lanceolate (1), or elliptic (1), or oblong (1); 1 length of upper glume; chartaceous; 1-keeled; 3 -veined. Lower glume surface smooth (2), or asperulous (1); without pits. Lower glume apex obtuse (2), or acute (1). Upper glume lanceolate (1), or elliptic (1), or oblong (1); 1 length of adjacent fertile lemma; chartaceous; 1-keeled; 3 -veined. Upper glume surface smooth (2), or asperulous (1). Upper glume apex obtuse (2), or acute (1).

FLORETS Fertile lemma elliptic (2), or ovate (1); thickened on margins at base; dorsally compressed; membranous; firmer on margins; keeled; wingless; 5 -veined. Lemma midvein without distinctive roughness (2), or scaberulous (1). Lemma surface smooth (2), or asperulous (1); unwrinkled; without grooves; glabrous (2), or pubescent (1). Lemma margins eciliate (1), or ciliate (2), or pubescent (1). Lemma apex entire (1), or dentate (2); 2 -fid (2/2); acute (1/1); muticous, or mucronate (2). Palea 0.75–0.8–0.85 length of lemma; 2 -veined. Palea keels pubescent (1), or ciliolate (2). Palea surface glabrous (2), or pilose (1). Apical sterile florets resembling fertile though underdeveloped.

FLOWER Anthers 1. Ovary glabrous.

FRUIT Caryopsis with adherent pericarp; oblong (1/1); dorsally compressed (1/1); concavo-convex (1/1). Hilum punctiform (2/2).

DISTRIBUTION South America.

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