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.

Trisetaria

HABIT Annual. Culms erect (12/12), or geniculately ascending (10/12); slender (1/1); 4–23.82–80 cm long. Lateral branches lacking (1/1), or sparse (1/1). Ligule an eciliate membrane (15), or a ciliolate membrane (1). Leaf-blades linear (15), or lanceolate (1). Leaf-blade midrib conspicuous (2/2).

INFLORESCENCE Inflorescence a panicle; subtended by an unspecialized leaf-sheath (15), or an inflated leaf-sheath (2); exserted (14), or embraced at base by subtending leaf (2).

Panicle open (2), or contracted (8), or spiciform (6), or capitate (1).

Spikelets solitary. Fertile spikelets pedicelled. Pedicels oblong (4/4).

FERTILE SPIKELETS Spikelets comprising 1 fertile florets (2), or 2 fertile florets (11), or 3 fertile florets (6), or 4–5 fertile florets (3); with a barren rhachilla extension (11), or with diminished florets at the apex (5). Spikelets oblong (5), or cuneate (13); laterally compressed; 2–4.657–7.8 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes definite (15/15); glabrous (6/15), or pubescent (6/15), or pilose (3/15), or villous (2/15). Floret callus glabrous (5/10), or pubescent (5/10).

GLUMES Glumes persistent; shorter than spikelet (4), or reaching apex of florets (2), or exceeding apex of florets (11); thinner than fertile lemma (11), or similar to fertile lemma in texture (4), or firmer than fertile lemma (1); parallel to lemmas (1), or gaping (15). Lower glume linear (5), or lanceolate (10), or elliptic (1), or oblong (2), or ovate (1); 0.5–0.8781–1 length of upper glume; hyaline (3), or membranous (11), or chartaceous (1), or cartilaginous (1); without keels (1), or 1-keeled (15); 1 -veined (10), or 2 -veined (2), or 3 -veined (7). Lower glume lateral veins absent (9), or distinct (6), or unequally thickened (1); without ribs (6/7), or ribbed (1/7). Lower glume surface smooth (14), or asperulous (2); without pits; glabrous (13), or puberulous (1), or pubescent (1), or pilose (1), or villous (1), or setose (1). Lower glume apex obtuse (1), or acute (3), or acuminate (11), or attenuate (3); muticous (13), or mucronate (3), or awned (2). Upper glume lanceolate (12), or elliptic (2), or oblong (2), or ovate (2); 0.8–1.287–2 length of adjacent fertile lemma; hyaline (3), or membranous (11), or chartaceous (1), or cartilaginous (1); with undifferentiated margins (15), or hyaline margins (1); 1-keeled; 3 -veined. Upper glume primary vein eciliate (15), or pectinately ciliate (1). Upper glume lateral veins without ribs (15), or ribbed (1). Upper glume surface smooth (14), or asperulous (2); glabrous (13), or puberulous (1), or pilose (2), or villous (1), or setose (1). Upper glume apex entire, or dentate (1); 2 -fid (1/1); obtuse (1), or acute (3), or acuminate (12), or attenuate (2); muticous (12), or mucronate (3), or awned (3); 1 -awned (3/3).

FLORETS Fertile lemma lanceolate (11), or elliptic (1), or oblong (3), or obovate (2); membranous (14), or cartilaginous (2); of similar consistency on margins (14), or much thinner on margins (2); without keel (12), or keeled (4); wingless; 3 -veined (4), or 4 -veined (1), or 5 -veined (13). Lemma midvein without distinctive roughness (11), or scaberulous (4), or scabrous (1). Lemma lateral veins obscure (3/3). Lemma surface smooth (13), or asperulous (1), or scaberulous (1), or scabrous (1), or punctate (1); unwrinkled; without grooves; glabrous (14), or pubescent (4), or villous (1). Lemma margins eciliate (15), or ciliolate (1), or pubescent (1). Lemma apex entire (2), or dentate (12), or lobed (2); 2 -fid (14/14); incised 0.25–0.29–0.33 of lemma length; acute (1/3), or acuminate (2/3); mucronate (1), or awned; 1 -awned (6), or 3 -awned (10). Principal lemma awn apical (1), or subapical (3), or from a sinus (1), or dorsal (11); straight (5), or curved (3), or geniculate (12). Lateral lemma awns shorter than principal (9/9). Palea gaping; 0.66–0.7675–1 length of lemma; hyaline. Palea keels smooth (5), or scaberulous (5), or scabrous (6). Palea apex dentate (6/7), or lobed (1/7); muticous (15), or with excurrent keel veins (1), or awned (1). Apical sterile florets resembling fertile though underdeveloped (3/5), or distinct from fertile (2/5).

FLOWER Lodicules 2 (7/7); membranous (6/6). Anthers 3. Ovary glabrous (15/15).

FRUIT Caryopsis with adherent pericarp (15/15); lanceolate (1/2), or fusiform (1/2); laterally compressed (1/1); concavo-convex (1/1). Embryo 0.1–0.1312–0.15 length of caryopsis. Hilum punctiform (15/15).

DISTRIBUTION Europe (10), or Africa (9), or Temperate Asia (6), or Tropical Asia (1).

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