Eustachys

HABIT Perennial. Rhizomes absent (12), or short (1). Stolons absent (11), or present (2). Culms erect (10/10), or decumbent (1/10); robust (1/1); 10–67.61–150 cm long; rooting from lower nodes (1/1). Culm-internodes elliptical in section (3/3). Lateral branches lacking (4/4). Ligule a ciliolate membrane (1), or a ciliate membrane (5), or a fringe of hairs (7).

INFLORESCENCE Inflorescence composed of racemes; exserted, or embraced at base by subtending leaf (1).

Racemes paired (2), or digitate; erect (2), or ascending (11); unilateral. Rhachis angular (8/9), or semiterete (1/9). Spikelet packing broadside to rhachis; crowded; 1 -rowed (3/5), or 2 -rowed (2/5).

Spikelets pectinate; solitary. Fertile spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; with diminished florets at the apex. Spikelets obovate; laterally compressed; 0.996–2.4–4.2 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus glabrous (6), or pubescent (3), or pilose (4).

GLUMES Glumes persistent; shorter than spikelet (12), or exceeding apex of florets (1); thinner than fertile lemma; gaping. Lower glume lanceolate (10), or elliptic (2), or ovate (1); 0.5–0.76–0.9 length of upper glume; membranous; without keels (10), or 1-keeled (3); 1 -veined. Lower glume lateral veins absent. Lower glume surface without pits; glabrous (11), or puberulous (2). Lower glume apex emarginate (2), or obtuse (1), or acute (11); muticous (12), or mucronate (2). Upper glume lanceolate (1), or oblong (12); 0.5–0.8004–1.25 length of adjacent fertile lemma; membranous; without keels; 1 -veined. Upper glume surface smooth (10), or asperulous (1), or scabrous (2); glabrous (10), or puberulous (3). Upper glume apex entire (4), or lobed (9); 2 -fid (9/9); emarginate (1), or truncate (2), or obtuse (10), or acute (1); mucronate (2), or awned (12); 1 -awned (12/12). Upper glume awn terminal (9), or subapical (3), or oblique (1).

FLORETS Fertile lemma elliptic (1), or ovate (9), or oblate (3); laterally compressed; not gibbous (12), or gibbous (1); chartaceous (10), or coriaceous (3); of similar consistency above (12), or much thinner above (1); keeled; wingless; 3 -veined. Lemma midvein eciliate (7), or ciliolate (1), or ciliate (4), or pubescent (2). Lemma surface smooth (11), or asperulous (2); unwrinkled; without grooves; glabrous (12), or pubescent (2). Lemma margins eciliate (2), or ciliate (8), or pubescent (4). Lemma apex emarginate (3), or obtuse (4), or acute (6); muticous (9), or mucronate (8), or awned (1); 1 -awned (1/1). Principal lemma awn apical (7/8), or subapical (1/8). Palea 0.9–0.95–1 length of lemma; 2 -veined. Palea keels smooth (11), or scaberulous (3); eciliate (12), or ciliolate (2). Apical sterile florets 1 in number, or 2 in number (1); barren; elliptic (2), or oblong (5), or cuneate (6). Apical sterile lemmas muticous (11), or mucronate (1), or awned (2).

FLOWER Lodicules 2 (2/2). Anthers 3 (6/6).

FRUIT Caryopsis with adherent pericarp (4/5), or tardily free pericarp (1/5); ellipsoid (2/2); isodiametric (1/1); trigonous (5/5). Embryo 0.5 length of caryopsis. Hilum punctiform (3/3).

DISTRIBUTION Africa (1), or Temperate Asia (2), or Tropical Asia (1), or Australasia (1), or Pacific (1), or North America (5), or South America (9).

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