Tridens

HABIT Perennial. Rhizomes absent (10), or short (3), or elongated (2). Culms erect (9/9); robust (1/1); 20–77.5–180 cm long. Lateral branches lacking (2/2). Ligule a ciliate membrane (3), or a fringe of hairs (12).

INFLORESCENCE Inflorescence a panicle, or composed of racemes (1); terminal (14), or terminal and axillary (1).

Panicle open (9), or contracted (5), or spiciform (1).

Racemes borne along a central axis (1/1).

Spikelets appressed (2/2), or ascending (1/2); solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 3–7–15 fertile florets; with diminished florets at the apex. Spikelets elliptic (1), or oblong (12), or ovate (1), or orbicular (1), or cuneate (1); laterally compressed; 4–7.343–15 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes definite. Floret callus glabrous (1/9), or pubescent (8/9).

GLUMES Glumes persistent; shorter than spikelet (14), or reaching apex of florets (1); thinner than fertile lemma (6), or similar to fertile lemma in texture (9). Lower glume lanceolate (4), or oblong (8), or ovate (3); 0.25–0.884–1.2 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume surface without pits. Lower glume apex emarginate (2), or obtuse (6), or acute (12), or acuminate (2); muticous (7), or mucronate (8). Upper glume lanceolate (4), or oblong (8), or ovate (3); 0.5–1.03–2 length of adjacent fertile lemma; membranous; 1-keeled; 1 -veined. Upper glume apex emarginate (1), or obtuse (7), or acute (11), or acuminate (2); muticous (12), or mucronate (3).

FLORETS Fertile lemma lanceolate (3), or elliptic (9), or oblong (2), or ovate (2); membranous (9), or chartaceous (6); without keel; wingless; 3 -veined. Lemma midvein eciliate (1), or ciliate (3), or pubescent (11). Lemma lateral veins obscure (1/1); excurrent (12), or extending close to apex (5). Lemma surface unwrinkled; without grooves. Lemma margins eciliate (1), or ciliate (5), or pubescent (9). Lemma apex entire (3), or dentate (12); 2 -fid (11/12), or 3 -fid (1/12); emarginate (3/4), or obtuse (3/4); muticous (1), or mucronate (13), or awned (2); 1 -awned (1/2), or 3 -awned (1/2). Principal lemma awn apical (14), or from a sinus (1). Palea 0.6–0.8786–1 length of lemma; 2 -veined (1/1). Palea keels smooth (12), or scabrous (2), or tuberculate (1); eciliate (13), or pubescent (1), or ciliolate (1). Palea apex dentate (2/2). Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2 (1/1); fleshy (1/1). Anthers 3 (5/5).

FRUIT Caryopsis with adherent pericarp; lanceolate (1/11), or ellipsoid (4/11), or oblong (5/11), or ovoid (1/11), or obovoid (1/11); dorsally compressed (3/3); plano-convex (1/2), or concavo-convex (1/2); reticulate (1/1). Embryo 0.4–0.425–0.5 length of caryopsis. Hilum punctiform (4/5), or elliptic (1/5).

DISTRIBUTION Africa (1), or North America (9), or South America (5).

Please cite this publication as detailed in How to Cite Version: 3rd February 2016.