Otachyrium

HABIT Annual (1), or perennial (7). Rhizomes absent (3), or short (3), or elongated (2). Culms erect (6), or decumbent (2); robust (1/1); 10–56.18–150 cm long; spongy (1), or firm (7); without nodal roots (2/4), or rooting from lower nodes (2/4). Culm-nodes constricted (4/5), or swollen (1/5). Lateral branches lacking (4/5), or sparse (1/5), or ample (1/5). Ligule an eciliate membrane (6), or a ciliolate membrane (2), or absent (1). Leaf-blades filiform (1), or linear (6), or lanceolate (2); stiff (1), or firm (7). Leaf-blade midrib indistinct (1/1).

INFLORESCENCE Inflorescence a panicle; terminal (7), or terminal and axillary (1).

Panicle open (5), or contracted (3).

Spikelets solitary (1), or in pairs (7). Fertile spikelets pedicelled; 2 in the cluster (7/7). Pedicels tip discoid (2/4), or cupuliform (2/4).

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets ovate, or orbicular (1); laterally compressed (2), or dorsally compressed (6); symmetrical (5), or gibbous (3); 1.66–2.747–7.5 mm long; falling entire.

GLUMES Glumes shorter than spikelet; thinner than fertile lemma. Lower glume ovate; membranous; without keels (3/7), or 1-keeled (4/7); 1 -veined (7/7), or 2–3 -veined (5/7), or 4–5 -veined (2/7). Lower glume lateral veins absent (3), or distinct (6). Lower glume surface without pits. Lower glume apex obtuse (2/7), or acute (5/7). Upper glume oblong (1), or ovate (3), or orbicular (4); 0.33–0.3725–0.5 length of adjacent fertile lemma; membranous; without keels (5), or 1-keeled (3); 3 -veined (2/7), or 5 -veined (5/7), or 6–7 -veined (3/7). Upper glume apex truncate (3/7), or obtuse (1/7), or acute (3/7).

FLORETS Basal sterile florets male; with palea. Lemma of lower sterile floret oblong (1), or ovate (7); membranous (1), or chartaceous (6), or coriaceous (1); 3 -veined (7/7), or 4–7 -veined (1/7); without grooves (5), or sulcate (3); obtuse (1), or acute (7). Palea of lower sterile floret hyaline (1), or becoming indurate on keels at maturity (7); winged on keels, or winged on margins (4). Fertile lemma ovate; not gibbous (7), or gibbous (1); chartaceous (2), or coriaceous (1), or indurate (5); without keel (7), or keeled (1); wingless; 3 -veined (5/6), or 5 -veined (1/6). Lemma lateral veins obscure (2/2). Lemma surface smooth (7), or papillose (1); unwrinkled; without grooves. Lemma margins involute. Lemma apex acute (6/7), or cuspidate (1/7); without ornament (7), or laterally pinched (1). Palea membranous (1), or chartaceous (1), or coriaceous (1), or indurate (5); 0 -veined (1/1).

FRUIT Caryopsis with adherent pericarp; ovoid (6/7), or obovoid (1/7); dorsally compressed (1/1); plano-convex (1/1). Embryo 0.5 length of caryopsis. Hilum elliptic (6/6).

DISTRIBUTION South America.

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