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.

Elymus

HABIT Annual (1), or perennial (240). Rhizomes absent (195), or short (31), or elongated (21). Stolons absent (239), or present (2). Culms erect (140/169), or geniculately ascending (85/169), or decumbent (8/169), or prostrate (2/169); robust (2/13), or slender (10/13), or weak (1/13); 10–66.16–200 cm long; rooting from lower nodes (2/2). Culm-nodes constricted (2/2). Lateral branches lacking (5/5). Leaf-sheaths tubular for much of their length (1/1). Leaf-sheath auricles absent (178), or falcate (72). Ligule an eciliate membrane (238), or a ciliolate membrane (2), or absent (3). Leaf-blades aciculate (2), or filiform (8), or linear (231), or lanceolate (3); herbaceous (237), or coriaceous (4); stiff (31), or firm (209), or flaccid (3); without exudate (240), or pruinose (1). Leaf-blade margins unthickened (2/5), or cartilaginous (3/5). Leaf-blade apex muticous (236), or pungent (5).

INFLORESCENCE Inflorescence composed of racemes; exserted (238), or embraced at base by subtending leaf (6).

Racemes single; erect (30), or ascending (184), or drooping (37), or deflexed (2); linear (235), or moniliform (1), or oblong (7), or ovate (2), or obovate (1); unilateral (2), or bilateral (240); bearing few fertile spikelets (7), or many spikelets (234); bearing 1–9–25 fertile spikelets on each. Rhachis tough (235), or fragile at the nodes (6); flattened (201/205), or angular (1/205), or semiterete (4/205); terminating in a spikelet, or sterile spikelet (1). Spikelet packing broadside to rhachis; crowded (19), or contiguous (153), or lax (66), or distant (5); 2 -rowed (42/42). Rhachis internodes indefinite (114), or linear (115), or oblong (11), or clavate (1); falling with spikelet above (6/6). Rhachis internode tip flat (53/53).

Spikelets appressed (27/38), or ascending (5/38), or spreading (6/38), or pectinate (2/38), or deflexed (1/38); solitary (209), or in pairs (40), or in threes (4), or clustered at each node (3). Fertile spikelets sessile (239), or sessile and pedicelled (2), or pedicelled (11); 1 in the cluster (2/12), or 2 in the cluster (11/12), or 3 in the cluster (6/12), or 4 in the cluster (4/12). Pedicels oblong (4/4).

STERILE SPIKELETS Basal sterile spikelets absent (238), or rudimentary (3), or well-developed (2).

FERTILE SPIKELETS Spikelets comprising 0–1 basal sterile florets (2/2); 1–5–20 fertile florets; with a barren rhachilla extension (4), or with diminished florets at the apex (237). Spikelets linear (2/218), or lanceolate (25/218), or elliptic (170/218), or oblong (183/218), or ovate (4/218), or rhomboid (1/218), or cuneate (6/218); laterally compressed (234), or dorsally compressed (7); 5.81–15.93–80 mm long; falling entire (10), or breaking up at maturity (232); deciduous from the base (8/10), or with accessory branch structures (2/10); disarticulating below each fertile floret (225/232), or between fertile florets but the lowest falling with glumes attached (1/232), or above glumes but not between florets (6/232). Spikelet callus glabrous (9/9); base truncate (24/25), or acute (1/25). Rhachilla internodes definite (240/240); glabrous (139/240), or sparsely hairy (8/240), or pubescent (85/240), or pilose (9/240). Floret callus brief (237), or evident (4); glabrous (9/65), or sparsely hairy (3/65), or pubescent (43/65), or pilose (10/65), or bearded (3/65); obtuse (240), or acute (1).

GLUMES Glumes both absent or obscure (3), or one the lower absent or obscure (1), or two (240); distichous (192), or lateral (1), or collateral (48); persistent (217/218), or deciduous (1/218); shorter than spikelet (194/203), or reaching apex of florets (6/203), or exceeding apex of florets (4/203); parallel to lemmas (239), or gaping (2). Lower glume subulate (8/240), or linear (10/240), or lanceolate (176/240), or elliptic (25/240), or oblong (61/240), or ovate (9/240), or obovate (2/240); not gibbous (238/240), or gibbous (2/240); 0.5–0.934–1.25 length of upper glume; membranous (5/234), or chartaceous (1/234), or herbaceous (1/234), or coriaceous (227/234); without keels (215/230), or 1-keeled (15/230); 0–4–11 -veined. Lower glume lateral veins absent (13/240), or obscure (6/240), or distinct (217/240), or prominent (11/240); without ribs (182/234), or ribbed (52/234). Lower glume surface smooth (148/240), or asperulous (19/240), or scabrous (87/240); without pits (240/240); glabrous (220/240), or puberulous (3/240), or pubescent (11/240), or pilose (9/240), or hirsute (3/240), or villous (1/240), or hispidulous (2/240). Lower glume apex entire (231/240), or erose (2/240), or with a unilateral tooth (15/240), or dentate (8/240), or lobed (1/240); 1 -fid (3/9), or 2 -fid (8/9), or 3 -fid (2/9), or 4–9 -fid (1/9); emarginate (2/226), or truncate (8/226), or obtuse (21/226), or acute (106/226), or acuminate (101/226), or attenuate (12/226), or setaceously attenuate (16/226); muticous (164/232), or mucronate (39/232), or awned (75/232). Upper glume subulate (9), or linear (8), or lanceolate (172), or elliptic (26), or oblong (67), or ovate (8), or obovate (2); not gibbous (239), or gibbous (2); 0.25–0.9048–9 length of adjacent fertile lemma; membranous (5/234), or chartaceous (1/234), or herbaceous (1/234), or coriaceous (227/234); with undifferentiated margins (194), or hyaline margins (12), or membranous margins (27), or scarious margins (9); without keels (215/230), or 1-keeled (15/230); 0–4–11 -veined. Upper glume primary vein eciliate (240), or ciliate (1). Upper glume lateral veins without ribs (184/237), or ribbed (53/237). Upper glume surface smooth (150), or asperulous (20), or scabrous (85); glabrous (223), or puberulous (4), or pubescent (8), or pilose (9), or hirsute (3), or villous (1), or hispidulous (2). Upper glume apex entire (232), or erose (2), or with a unilateral tooth (16), or dentate (7); 1 -fid (3/7), or 2 -fid (6/7), or 3 -fid (2/7), or 4–9 -fid (1/7); emarginate (3/227), or truncate (8/227), or obtuse (20/227), or acute (105/227), or acuminate (103/227), or attenuate (12/227), or setaceously attenuate (15/227); muticous (160/232), or mucronate (36/232), or awned (79/232); 1 -awned (77/78), or 3–9 -awned (1/78).

FLORETS Basal sterile florets barren (2/2); without significant palea (2/2). Lemma of lower sterile floret subulate (1/2), or linear (1/2), or oblong (1/2); coriaceous (1/1); awned (1/1). Fertile lemma lanceolate (178), or elliptic (68), or oblong (105), or ovate (5); chartaceous (3), or coriaceous (238); of similar consistency on margins (233), or much thinner on margins (8); without keel (46/91), or keeled (45/91); wingless; 3–4 -veined (2/232), or 5 -veined (231/232), or 6 -veined (22/232), or 7 -veined (23/232), or 8–11 -veined (1/232). Lemma midvein without distinctive roughness (238), or scaberulous (2), or scabrous (1). Lemma lateral veins obscure (7/12), or distinct (2/12), or prominent (3/12); without ribs (234), or ribbed (7). Lemma surface smooth (177), or asperulous (6), or scaberulous (34), or scabrous (41), or papillose (1); unwrinkled; without grooves; glabrous (159), or puberulous (31), or pubescent (43), or pilose (17), or hirsute (5), or villous (9), or hispidulous (6); hairy on back (105/108), or on veins (2/108), or between veins (1/108). Lemma margins eciliate (222), or ciliolate (5), or ciliate (8), or pubescent (10), or villous (1). Lemma apex entire (227), or dentate (16); 1 -fid (2/16), or 2 -fid (14/16), or 3 -fid (2/16); emarginate (9/203), or truncate (4/203), or obtuse (17/203), or acute (130/203), or acuminate (48/203), or attenuate (7/203), or apiculate (1/203); muticous (41), or mucronate (20), or awned (205); 1 -awned (204/206), or 3 -awned (2/206). Principal lemma awn apical (210/220), or from a sinus (11/220); straight (174/220), or curved (63/220), or flexuous (7/220); 0.9–1–1.1 length of lemma. Lateral lemma awns shorter than principal (1/1). Palea 0.66–0.9788–1.1 length of lemma; membranous (239), or coriaceous (2); 2 -veined (78/78). Palea keels wingless (234), or winged (7); smooth (177), or scaberulous (8), or scabrous (57), or tuberculate (1); eciliate (134), or ciliolate (83), or ciliate (24). Palea surface glabrous (196), or puberulous (33), or pubescent (11), or pilose (3), or hirsute (1). Palea apex dentate (5/5); muticous (240), or with excurrent keel veins (2). Apical sterile florets resembling fertile though underdeveloped (235/237), or distinct from fertile (2/237); rudimentary (1/1).

FLOWER Lodicules 2 (175/175); membranous (171/171); glabrous (169/175), or ciliate (6/175); 2-toothed (1/1). Anthers 3 (228/228). Stigmas 2 (171/171). Ovary unappendaged (238), or with a fleshy appendage below style insertion (3); pubescent on apex (156/156).

FRUIT Caryopsis with adherent pericarp (195/195); linear (1/20), or lanceolate (2/20), or fusiform (3/20), or ellipsoid (1/20), or oblong (11/20), or obovoid (3/20); isodiametric (4/4); smooth (4/4); apex unappendaged (26/26). Embryo 0.15–0.1955–0.25 length of caryopsis. Hilum linear (46/46); 0.9–0.9333–1 length of caryopsis.

DISTRIBUTION Europe (25), or Africa (9), or Temperate Asia (173), or Tropical Asia (30), or Australasia (15), or Pacific (1), or North America (41), or South America (10), or Antarctica (2).

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