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.

Sporobolus

HABIT Annual (47), or perennial (142). Rhizomes absent (156), or short (19), or elongated (13). Stolons absent (179), or present (9). Culms erect (135/151), or geniculately ascending (25/151), or decumbent (5/151), or prostrate (5/151); robust (6/21), or of moderate stature (1/21), or slender (14/21); 2.5–53.83–390 cm long; firm (180), or wiry (6). Culm-internodes channelled (1/3), or elliptical in section (2/3). Culm-nodes constricted (1/2), or flush with internodes (1/2). Lateral branches lacking (42/48), or sparse (10/48), or ample (1/48). Leaves differentiated into sheath and blade (185), or without demarcation between sheath and blade (1). Ligule an eciliate membrane (3), or a ciliolate membrane (3), or a ciliate membrane (1), or a fringe of hairs (178), or absent (2). Leaf-blade base without a false petiole (185), or with a brief petiole-like connection to sheath (1). Leaf-blades filiform (21), or linear (163), or lanceolate (12); herbaceous (183), or coriaceous (3); stiff (27), or firm (156), or flaccid (3). Leaf-blade midrib indistinct (2/4), or evident (1/4), or widened (2/4). Leaf-blade margins cartilaginous (8/8). Leaf-blade apex muticous (180), or pungent (6).

INFLORESCENCE Inflorescence a panicle; terminal (181), or terminal and axillary (5); subtended by an unspecialized leaf-sheath (182), or an inflated leaf-sheath (5); exserted (178), or embraced at base by subtending leaf (11), or enclosed (4).

Panicle open (137/185), or contracted (32/185), or spiciform (31/185). Primary panicle branches not whorled (115), or whorled at lower nodes (15), or whorled at most nodes (60); without sterile bristles (185), or sterile at lowest node (1).

Spikelets appressed (16/17), or ascending (1/17), or spreading (2/17); solitary (185/185), or in pairs (2/185). Fertile spikelets sessile (8), or pedicelled (184); 2 in the cluster (1/1). Pedicels filiform (9/17), or linear (6/17), or oblong (2/17); tip widened (1/1).

FERTILE SPIKELETS Spikelets comprising 1 fertile florets, or 2 fertile florets (1); without rhachilla extension (184), or with a barren rhachilla extension (2). Spikelets linear (1), or lanceolate (150), or elliptic (33), or oblong (2), or orbicular (1), or obovate (1); laterally compressed (3), or subterete (183); 0.581–2.365–7.5 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes definite (1/1).

GLUMES Glumes one the lower absent or obscure (2), or two; persistent (2/184), or deciduous (182/184); shorter than spikelet (94), or reaching apex of florets (81), or exceeding apex of florets (22); thinner than fertile lemma (7), or similar to fertile lemma in texture (179); parallel to lemmas (181), or gaping (5). Lower glume linear (6), or lanceolate (83), or elliptic (20), or oblong (41), or ovate (52), or orbicular (1); 0–0.5675–1.1 length of upper glume; hyaline (44/179), or membranous (136/179); without keels (182/184), or 1-keeled (2/184); 0 -veined (66/170), or 1 -veined (111/170). Lower glume lateral veins absent (175), or distinct (11). Lower glume surface smooth (178), or asperulous (8), or scabrous (3); without pits; glabrous (185), or puberulous (1). Lower glume apex entire (180), or erose (7), or dentate (1), or lobed (1); truncate (10/184), or obtuse (50/184), or acute (119/184), or acuminate (23/184). Upper glume lanceolate (45), or elliptic (33), or oblong (24), or ovate (89); 0.3–0.8463–2 length of adjacent fertile lemma; hyaline (31/183), or membranous (151/183), or cartilaginous (1/183); with undifferentiated margins (184), or hyaline margins (2); without keels (180/184), or 1-keeled (4/184); 0 -veined (11/185), or 1 -veined (175/185), or 2 -veined (3/185), or 3 -veined (5/185). Upper glume surface smooth (179), or asperulous (16), or scabrous (3), or spinose (1); glabrous (183), or puberulous (2), or hispidulous (1). Upper glume apex entire (184), or erose (3), or dentate (1); truncate (6/185), or obtuse (23/185), or acute (150/185), or acuminate (20/185), or attenuate (2/185), or setaceously attenuate (1/185), or cuspidate (3/185); muticous (183), or mucronate (3), or awned (1); 1 -awned (1/1).

FLORETS Fertile lemma lanceolate (31/185), or elliptic (30/185), or oblong (16/185), or ovate (114/185); hyaline (4/183), or membranous (177/183), or chartaceous (1/183), or cartilaginous (1/183); without keel (181/185), or keeled (4/185); wingless; 0 -veined (3/184), or 1 -veined (173/184), or 2 -veined (2/184), or 3 -veined (9/184). Lemma midvein without distinctive roughness (181/184), or scaberulous (2/184), or scabrous (1/184). Lemma lateral veins obscure (1/2), or distinct (1/2). Lemma surface smooth (181), or asperulous (3), or scaberulous (14), or scabrous (1); unwrinkled; without grooves; glabrous (181), or puberulous (3), or pubescent (2), or hispidulous (2). Lemma apex entire (183), or erose (3); truncate (3/185), or obtuse (21/185), or acute (159/185), or acuminate (7/185), or apiculate (1/185); muticous, or mucronate (1). Palea embraced by lemma (156), or gaping (1), or readily splitting down midline (30); 0.5–0.9867–2 length of lemma; 1 -veined (1/184), or 2 -veined (183/184). Palea keels separated (5), or approximate (181); wingless (184), or winged (2); smooth (185), or scaberulous (1). Palea surface glabrous (185), or pubescent (1). Palea apex entire (4/4), or dentate (1/4).

FLOWER Lodicules 2 (12/12). Anthers 1 (1/138), or 2 (18/138), or 3 (123/138).

FRUIT Caryopsis with free soft pericarp (184/185), or free brittle pericarp (1/185); fusiform (2/123), or ellipsoid (53/123), or oblong (23/123), or ovoid (10/123), or orbicular (14/123), or obovoid (34/123), or square (1/123); isodiametric (7/37), or laterally compressed (27/37), or flattened (3/37); biconvex (2/16), or quadrangular (14/16); striate (3/5), or rugose (3/5). Embryo 0.25–0.4618–0.75 length of caryopsis. Hilum punctiform (1/1).

CLEISTOGENES AND VIVIPARY Cleistogenes absent (185), or present (1); in upper sheaths (1/1).

DISTRIBUTION Europe (2), or Africa (85), or Temperate Asia (30), or Tropical Asia (30), or Australasia (23), or Pacific (11), or North America (40), or South America (45), or Antarctica (1).

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