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.

Tetrapogon

HABIT Annual (2), or perennial. Rhizomes absent (3), or short (2). Culms erect (4), or geniculately ascending (4), or decumbent (1); 15–49.9–104 cm long. Ligule a ciliolate membrane. Leaf-blades filiform (1), or linear (4).

INFLORESCENCE Inflorescence composed of racemes; subtended by an unspecialized leaf-sheath (4), or an inflated leaf-sheath (1); exserted (4), or embraced at base by subtending leaf (1).

Racemes single (2), or paired (4), or digitate (1); side by side (4), or appressed back to back (1); erect (1), or ascending (4); unilateral. Rhachis angular (4/4). Spikelet packing broadside to rhachis; 2 -rowed (4/4).

Spikelets ascending (4/4); solitary. Fertile spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets (2), or 2 fertile florets (1), or 3 fertile florets (4), or 4–5 fertile florets (3), or 6–7 fertile florets (1); with diminished florets at the apex. Spikelets cuneate; laterally compressed; 2–5.1–12 mm long; breaking up at maturity; disarticulating below each fertile floret (1), or above glumes but not between florets (4). Rhachilla internodes definite (4/4). Floret callus pilose.

GLUMES Glumes persistent; shorter than spikelet (2), or reaching apex of florets (1), or exceeding apex of florets (3); thinner than fertile lemma; gaping. Lower glume lanceolate; 0.6–0.731–0.8 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume surface without pits. Lower glume apex acute (1), or acuminate, or setaceously attenuate (2); muticous, or mucronate (1). Upper glume lanceolate (4), or ovate (1); 0.8–1.47–2 length of adjacent fertile lemma; membranous; 1-keeled; 1 -veined. Upper glume apex truncate (1), or obtuse (1), or acute (2), or acuminate (4), or setaceously attenuate (2); muticous (4), or mucronate (2).

FLORETS Fertile lemma elliptic (1), or ovate (2), or obovate (1), or cuneate (1); laterally compressed (1/1); elliptic in profile (1/1); coriaceous; of similar consistency on margins (4), or much thinner on margins (1); keeled; wingless (4), or winged on margins (1); 3 -veined. Lemma midvein eciliate (2), or ciliate (3). Lemma surface unwrinkled; without grooves; glabrous (4), or pubescent (1); without hair tufts (4), or with conspicuous apical hairs (1). Lemma margins eciliate (2), or ciliolate (1), or ciliate (3). Lemma apex entire (4), or dentate (1); 2 -fid (1/1); obtuse (1/4), or acute (3/4); awned; 1 -awned. Principal lemma awn subapical. Palea 2 -veined (4/4). Palea keels eciliate (1), or ciliolate (4). Apical sterile florets 1 in number (2), or 2 in number (4), or 3 in number (3), or 4–6 in number (1); barren; separate (1), or in a clump (4); elliptic (1), or cuneate (4). Apical sterile lemmas muticous (1), or awned (4).

FLOWER Lodicules 2 (1/1); fleshy (1/1). Anthers 3 (1/1). Stigmas 2 (1/1).

FRUIT Caryopsis with adherent pericarp (1), or free soft pericarp (4); oblong (3/4), or obovoid (1/4); dorsally compressed (4/4); biconvex (4), or trigonous (1). Hilum punctiform (1/1).

DISTRIBUTION Africa, or Temperate Asia (3), or Tropical Asia (2).

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