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.

Trichoneura

HABIT Annual (6), or perennial (2). Culms erect (2/7), or geniculately ascending (6/7), or decumbent (5/7); 3–41–110 cm long; rooting from lower nodes (1/1). Ligule an eciliate membrane. Leaf-blades persistent (7), or deciduous at the ligule (1); stiff (1), or firm (7).

INFLORESCENCE Inflorescence composed of racemes; not deciduous as a whole (7), or deciduous as a whole (1). Peduncle persistent (7), or fracturing (1).

Racemes borne along a central axis; appressed (1), or ascending (6), or spreading (3); unilateral; bearing 8–9 fertile spikelets on each (1/1). Rhachis persistent (6), or deciduous from axis (2); angular. Spikelet packing broadside to rhachis; contiguous (7), or distant (1).

Spikelets appressed (7/7); solitary. Fertile spikelets sessile (3), or pedicelled (5). Pedicels oblong (4/4).

FERTILE SPIKELETS Spikelets comprising 4 fertile florets (4), or 5–6 fertile florets, or 7–8 fertile florets (4), or 9 fertile florets (2); with diminished florets at the apex. Spikelets cuneate; laterally compressed; 4–6.887–14 mm long; falling entire (2), or breaking up at maturity (6); deciduous with accessory branch structures (2/2); disarticulating below each fertile floret (6/6). Rhachilla internodes definite; glabrous (5), or pilose (3). Floret callus pubescent (6/7), or pilose (1/7).

GLUMES Glumes persistent (6/6); shorter than spikelet (5), or reaching apex of florets (4), or exceeding apex of florets (1); gaping. Lower glume linear (2), or lanceolate (7), or oblong (1); 0.75–0.9125–1.2 length of upper glume; membranous; without keels (2), or 1-keeled (6); 1 -veined. Lower glume lateral veins absent. Lower glume surface smooth (3), or asperulous (2), or scabrous (3); without pits. Lower glume apex acute (1), or acuminate (1), or attenuate (5), or setaceously attenuate (1); muticous (5), or awned (3). Upper glume linear (1), or lanceolate (6), or elliptic (1), or oblong (1); 1.25–1.778–2.3 length of adjacent fertile lemma; membranous; without keels (2), or 1-keeled (6); 1 -veined. Upper glume surface smooth (3), or asperulous (2), or scabrous (3). Upper glume apex acute (1), or acuminate (1), or attenuate (5), or setaceously attenuate (1); muticous (5), or awned (3); 1 -awned (3/3).

FLORETS Fertile lemma elliptic (1), or oblong; membranous; without keel (2), or keeled; wingless; 3 -veined. Lemma midvein without distinctive roughness (7), or scaberulous (1). Lemma surface unwrinkled; without grooves; glabrous (4), or puberulous (1), or pilose (3). Lemma margins ciliate. Lemma apex dentate; 2 -fid; obtuse (3/3); mucronate (1), or awned (7); 1 -awned (7/7). Principal lemma awn apical (1), or from a sinus (7). Palea 1 length of lemma; 2 -veined. Palea surface glabrous (7), or pubescent (3). Apical sterile florets resembling fertile though underdeveloped.

FLOWER Anthers 3 (7/7).

FRUIT Caryopsis with adherent pericarp (3/3); linear (1/3), or lanceolate (1/3), or ellipsoid (2/3), or oblong (2/3); dorsally compressed (3/3); plano-convex (3/3), or concavo-convex (3/3).

DISTRIBUTION Africa (5), or Temperate Asia (1), or North America (1), or South America (2).

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