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.

Streptostachys

HABIT Perennial. Rhizomes absent (2), or short (4), or elongated (1). Culms erect (4/4); robust (3/3); 35–115.2–200 cm long; without nodal roots (1/1), or rooting from lower nodes (1/1). Culm-internodes terete (2/3), or elliptical in section (1/3). Culm-nodes swollen (1/1). Lateral branches lacking (1/1). Ligule a ciliate membrane (1), or a fringe of hairs (6), or absent (3). Leaf-blade base without a false petiole (6), or with a brief petiole-like connection to sheath (1). Leaf-blades linear (2), or lanceolate (6), or ovate (1); stiff (2), or firm (5). Leaf-blade midrib indistinct (1/1). Leaf-blade apex muticous (6), or pungent (1).

INFLORESCENCE Inflorescence a panicle (5), or composed of racemes (2).

Panicle open (5/5). Primary panicle branches not whorled (4/5), or whorled at lower nodes (2/5), or whorled at most nodes (1/5).

Racemes digitate (1/2), or borne along a central axis (1/2). Rhachis angular (1/1). Spikelet packing contiguous (1/2), or distant (1/2).

Spikelets solitary (3), or in pairs (4). Fertile spikelets sessile and pedicelled (2), or pedicelled (5); 2 in the cluster (2/2). Pedicels free (6), or with the longest adnate below to rhachis (1); linear (2/6), or oblong (3/6), or clavate (2/6); tip discoid (1/1).

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate (1), or elliptic (4), or oblong (1), or ovate (2); dorsally compressed; 3.5–6.255–9.3 mm long; falling entire. Spikelet callus brief (1), or square (4), or toroidal (2); free from lower glume (2), or incorporating lowest rhachilla internode with adnate lower glume (5), or supplemented by thickened base of upper glume (4). Rhachilla internodes brief up to lowest fertile floret (1), or elongated between glumes (6), or elongated below basal sterile floret (5). Rhachilla elongation stout (5/5).

GLUMES Glumes one the lower absent or obscure (1), or two (6); shorter than spikelet (5), or reaching apex of florets (1), or exceeding apex of florets (1); thinner than fertile lemma, or similar to fertile lemma in texture (1). Lower glume lanceolate (1/6), or ovate (5/6); clasping (1/1); membranous (6/6); without keels (6/6); 1–2 -veined (1/6), or 3 -veined (4/6), or 4 -veined (2/6), or 5 -veined (4/6). Lower glume lateral veins absent (1/6), or distinct (6/6). Lower glume surface without pits (6/6); glabrous (3/6), or pubescent (2/6), or pilose (1/6). Lower glume apex acute (6/6). Upper glume lanceolate (1), or elliptic (1), or ovate (5); membranous (6), or coriaceous (1); without keels; 5 -veined (6), or 6 -veined (2), or 7 -veined (3). Upper glume lateral veins transversely connected at apex (2/2); parallel at apex (1/1). Upper glume surface glabrous (2), or puberulous (2), or pubescent (2), or pilose (1), or hispidulous (1). Upper glume apex obtuse (3/5), or acute (3/5), or acuminate (1/5).

FLORETS Basal sterile florets male (6), or barren (4); with palea (6), or without significant palea (1). Lemma of lower sterile floret elliptic (1), or ovate (6); membranous (6), or coriaceous (2); 3–4 -veined (2), or 5 -veined (6), or 6 -veined (1), or 7 -veined (2); obtuse (1/5), or acute (4/5). Fertile lemma elliptic (3), or ovate (5); indurate; without keel; wingless; 5 -veined (3/3). Lemma surface smooth (3), or scaberulous (1), or papillose (4); unwrinkled; without grooves; glabrous (5), or pubescent (2). Lemma margins involute. Lemma apex obtuse (3/3); without ornament (5), or pubescent (2). Palea 1 length of lemma; indurate; without keels.

FLOWER Lodicules 2 (5/5); fleshy (4/4); truncate (1/1). Anthers 3 (1/1).

FRUIT Caryopsis with adherent pericarp; ellipsoid (4/5), or oblong (1/5); dorsally compressed (4/4); plano-convex (1/1). Embryo 0.4 length of caryopsis. Hilum linear (5/5); 1 length of caryopsis.

DISTRIBUTION South America.

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