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.

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: 27th January 2014.