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.

Tragus

HABIT Annual (7), or perennial (1). Stolons absent (7), or present (1). Culms erect (5/6), or geniculately ascending (4/6), or decumbent (1/6); 3–23.25–65 cm long. Ligule a ciliolate membrane (1), or a fringe of hairs (7). Leaf-blades stiff (2), or firm (6). Leaf-blade margins cartilaginous (3/3).

INFLORESCENCE Inflorescence composed of racemes; subtended by an unspecialized leaf-sheath (7), or an inflated leaf-sheath (1).

Racemes borne along a central axis; not compacted (1), or in a multilateral false spike (7); spreading; oblong (5), or cuneate (3); bearing few fertile spikelets; bearing 1 fertile spikelets on each (1), or 2 fertile spikelets on each, or 3–4 fertile spikelets on each (4), or 5 fertile spikelets on each (2). Rhachis evident (5), or obsolete (3); deciduous from axis; subterete (5/5); terminating in a spikelet (1/5), or barren extension (4/5); extension subulate (3/4), or bristle-like (1/4). Raceme-bases brief (2), or filiform (2), or linear (4).

Spikelets solitary (4), or in pairs (4). Fertile spikelets sessile (7), or pedicelled (1); 2 in the cluster (3/3); subequal (1/4), or the upper smaller (3/4). Pedicels linear (1/1), or oblong (1/1).

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; subterete (6), or dorsally compressed (2); 2–4.309–10 mm long; falling entire; deciduous with accessory branch structures.

GLUMES Glumes one the lower absent or obscure (5), or two (5); exceeding apex of florets; firmer than fertile lemma. Lower glume lanceolate (2/5), or ovate (3/5); 0–0.12–0.2 length of upper glume; hyaline (5/5); without keels (3/3); 0 -veined (5/5). Lower glume lateral veins absent (3/5), or distinct (2/5). Lower glume surface without pits (5/5). Lower glume apex acute (3/3). Upper glume lanceolate (1), or elliptic (2), or ovate (5); 1–1.162–1.5 length of adjacent fertile lemma; membranous; without keels; 5 -veined (5), or 7 -veined (3). Upper glume lateral veins ribbed. Upper glume surface smooth (1), or spinose (1), or with hooked spines (6); glabrous (7), or puberulous (1), or setose (1); with simple hairs (1/2), or tubercle-based hairs (1/2). Upper glume apex acute (5), or acuminate (3).

FLORETS Fertile lemma lanceolate (1), or elliptic (2), or ovate (5); dorsally compressed (6/6); hyaline (2), or membranous (6); without keel; wingless; 3 -veined. Lemma surface unwrinkled; without grooves; glabrous (5), or puberulous (4). Lemma apex acuminate; muticous, or mucronate (1). Palea 1 length of lemma; hyaline (1), or membranous (7); 2 -veined. Palea apex erose (1/1).

FLOWER Lodicules 2; fleshy. Anthers 3.

FRUIT Caryopsis with adherent pericarp; ellipsoid (6/6); dorsally compressed (6/6); biconvex (5/5). Embryo 0.5 length of caryopsis. Hilum punctiform (1/1).

DISTRIBUTION Europe (1), or Africa (6), or Temperate Asia (3), or Tropical Asia (2), or Australasia (2), or Pacific (2), or North America (2), or South America (4).

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