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.

Ctenium

HABIT Annual (2), or perennial (18). Rhizomes absent (18), or short (1), or elongated (1). Culms erect (9/12), or geniculately ascending (3/12); 20–78.75–150 cm long; firm (17), or wiry (3). Leaf-sheath auricles absent (19), or erect (1). Ligule an eciliate membrane. Leaf-blades filiform (1), or linear (19); stiff (1), or firm (19); without scent (17), or aromatic (3).

INFLORESCENCE Inflorescence composed of racemes.

Racemes single (15), or paired (2), or digitate (6); erect (1), or ascending; unilateral. Rhachis semiterete (18/18); terminating in a barren extension; extension subulate. Spikelet packing broadside to rhachis; crowded; 2 -rowed.

Spikelets pectinate; solitary. Fertile spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 2 basal sterile florets; 1 fertile florets; without rhachilla extension (1), or with diminished florets at the apex (19). Spikelets cuneate; laterally compressed; 3.32–6.286–12 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus glabrous (1/18), or pubescent (2/18), or pilose (15/18).

GLUMES Glumes persistent; exceeding apex of florets; similar to fertile lemma in texture (3), or firmer than fertile lemma (17); gaping. Lower glume lanceolate (14), or ovate (6); 0.25–0.348–0.5 length of upper glume; hyaline (7), or membranous (8), or herbaceous (5); 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume surface smooth (19), or scabrous (1); without pits; glabrous (17), or pubescent (1), or hispidulous (2). Lower glume apex acute (6), or acuminate (10), or attenuate (1), or setaceously attenuate (4); muticous (17), or mucronate (3). Upper glume lanceolate (15), or elliptic (3), or ovate (2); 1.1–1.706–3 length of adjacent fertile lemma; membranous (3), or herbaceous (17); with undifferentiated margins (7), or hyaline margins (13); 1-keeled; 2 -veined (9), or 3 -veined (11). Upper glume primary vein eciliate (18), or ciliolate (1), or ciliate (1). Upper glume surface smooth (6), or asperulous (2), or scabrous (2), or tuberculate (10); glabrous (15), or puberulous (1), or hirsute (1), or hispidulous (3). Upper glume apex acute (6), or acuminate (13), or setaceously attenuate (3); awned; 1 -awned. Upper glume awn dorsal, or oblique.

FLORETS Basal sterile florets male (1/19), or barren (19/19); with palea (1/19), or without significant palea (19/19). Lemma of lower sterile floret lanceolate (4/19), or elliptic (9/19), or oblong (5/19), or ovate (2/19); 0.5–0.7419–1 length of fertile lemma; hyaline (1/19), or membranous (18/19); 3 -veined (10/10); emarginate (2/18), or truncate (1/18), or obtuse (5/18), or acute (10/18), or cuspidate (1/18); awned (19/19). Fertile lemma lanceolate (1), or elliptic (1), or ovate (18); membranous; keeled; wingless; 3 -veined. Lemma midvein eciliate (18), or ciliate (2). Lemma surface smooth (19), or scabrous (1); unwrinkled; without grooves; glabrous, or pilose (1); without hair tufts (19), or with conspicuous apical hairs (1). Lemma margins eciliate (1), or ciliate (14), or villous (5). Lemma apex entire (19), or dentate (1); 2 -fid (1/1); emarginate (1/11), or acute (10/11); muticous (1), or mucronate (1), or awned (18); 1 -awned (18/18). Principal lemma awn apical (1/19), or subapical (17/19), or dorsal (1/19). Palea 1 length of lemma; 2 -veined. Palea keels smooth (16), or scaberulous (2), or scabrous (1), or tuberculate (1); eciliate (16), or ciliolate (5). Palea surface glabrous (19), or pubescent (1). Palea apex dentate (1/1); muticous, or with excurrent keel veins (1). Apical sterile florets 1 in number (13/19), or 2 in number (7/19), or 3–4 in number (2/19); male (2/2), or barren (1/2); rudimentary (1/19), or linear (7/19), or lanceolate (2/19), or elliptic (8/19), or oblong (1/19), or ovate (1/19). Apical sterile lemmas muticous (11/19), or mucronate (3/19), or awned (7/19).

FLOWER Anthers 3 (1/1).

FRUIT Caryopsis with adherent pericarp (19/19); ellipsoid (2/3), or obovoid (1/3). Embryo 0.2 length of caryopsis.

DISTRIBUTION Africa (9), or Temperate Asia (1), or North America (4), or South America (7).

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