Leymus Hochst.

nonem

Habit

Perennial. Rhizomes absent (13), or short (12), or elongated (26). Culms erect (28/31), or geniculately ascending (8/31), or decumbent (1/31); robust (2/2); 10-69.4-350 cm long. Culm-internodes terete (1/1). Culm-nodes constricted (1/1). Lateral branches sparse (2/3), or fastigiate (1/3). Leaf-sheath auricles absent (41), or falcate (11). Ligule an eciliate membrane (48), or a ciliolate membrane (2). Leaf-blades filiform (1), or linear (49); herbaceous (14), or coriaceous (36); stiff (47), or firm (3). Leaf-blade apex muticous (48), or pungent (2).

Inflorescences

Inflorescence composed of racemes; exserted (49), or embraced at base by subtending leaf (1). Racemes single; erect (19), or ascending (30), or drooping (2); linear (48), or oblong (5); bilateral. Rhachis flattened (25/25). Spikelet packing broadside to rhachis; crowded (11), or contiguous (31), or lax (7), or distant (1); 2 -rowed (2/2). Rhachis internodes indefinite (24), or filiform (1), or linear (24), or oblong (1). Spikelets appressed (18/18); solitary (13), or in pairs (37), or in threes (19), or clustered at each node (6). Fertile spikelets sessile (45), or sessile and pedicelled (4), or pedicelled (3); 1 in the cluster (6/42), or 2 in the cluster (38/42), or 3 in the cluster (21/42), or 4 in the cluster (8/42), or 5 in the cluster (6/42), or 6 in the cluster (3/42), or 7-11 in the cluster (1/42).

Spikelets

Spikelets comprising 1-5-12 fertile florets; with diminished florets at the apex. Spikelets lanceolate (2), or elliptic (22), or oblong (27), or cuneate (1); laterally compressed; 6-14.91-32 mm long; breaking up at maturity; disarticulating below each fertile floret. Spikelet callus glabrous (2/4), or pilose (2/4); base truncate (2/2). Rhachilla internodes glabrous (35), or sparsely hairy (1), or pubescent (13), or pilose (1). Floret callus glabrous (2/7), or sparsely hairy (1/7), or pubescent (3/7), or pilose (2/7).

Fertile

Spikelets comprising 1-5-12 fertile florets; with diminished florets at the apex. Spikelets lanceolate (2), or elliptic (22), or oblong (27), or cuneate (1); laterally compressed; 6-14.91-32 mm long; breaking up at maturity; disarticulating below each fertile floret. Spikelet callus glabrous (2/4), or pilose (2/4); base truncate (2/2). Rhachilla internodes glabrous (35), or sparsely hairy (1), or pubescent (13), or pilose (1). Floret callus glabrous (2/7), or sparsely hairy (1/7), or pubescent (3/7), or pilose (2/7).

Glume

Glumes distichous (36), or collateral (14); persistent; shorter than spikelet (45/48), or reaching apex of florets (8/48), or exceeding apex of florets (3/48). Lower glume subulate (24), or linear (10), or lanceolate (20), or oblong (1); 0.5-0.9711-1 length of upper glume; chartaceous (2/36), or herbaceous (1/36), or coriaceous (33/36); without keels (1/11), or 1-keeled (10/11); 0 -veined (3/47), or 1 -veined (35/47), or 2 -veined (6/47), or 3 -veined (16/47), or 4-5 -veined (4/47), or 6-7 -veined (1/47). Lower glume lateral veins absent (27), or obscure (11), or distinct (17). Lower glume surface smooth (38), or asperulous (1), or scabrous (15); glabrous (43), or pubescent (7), or pilose (1), or villous (1). Lower glume apex acuminate (7/21), or attenuate (7/21), or setaceously attenuate (9/21); muticous (23/27), or awned (4/27). Upper glume subulate (24), or linear (10), or lanceolate (20), or oblong (1); 0.25-1.031-2 length of adjacent fertile lemma; chartaceous (2/36), or herbaceous (1/36), or coriaceous (33/36); with undifferentiated margins (42), or membranous margins (8); without keels (5/15), or 1-keeled (10/15); 0 -veined (2/47), or 1 -veined (36/47), or 2 -veined (6/47), or 3 -veined (15/47), or 4-5 -veined (4/47), or 6-7 -veined (1/47). Upper glume surface smooth (38), or scabrous (14); glabrous (43), or pubescent (7), or villous (1). Upper glume apex acuminate (6/21), or attenuate (7/21), or setaceously attenuate (9/21); muticous (23/27), or awned (4/27); 1 -awned (4/4).

Florets

Fertile lemma lanceolate (46), or elliptic (6), or oblong (4), or ovate (1); membranous (1), or chartaceous (10), or coriaceous (40); of similar consistency on margins (48), or much thinner on margins (2); without keel (39/47), or keeled (8/47); 5 -veined (45), or 6 -veined (7), or 7 -veined (12), or 8-9 -veined (2), or 10 -veined (1). Lemma lateral veins obscure (12/16), or distinct (2/16), or prominent (2/16); without ribs (49), or ribbed (1). Lemma surface smooth (45), or asperulous (2), or scaberulous (3), or scabrous (4); glabrous (27), or puberulous (7), or pubescent (13), or pilose (6), or villous (3). Lemma margins eciliate (40), or ciliate (7), or pubescent (4). Lemma apex entire (48), or dentate (2); 2 -fid (2/2); acute (22/46), or acuminate (23/46), or attenuate (2/46), or setaceously attenuate (1/46); muticous (21), or mucronate (9), or awned (32); 1 -awned (32/32). Principal lemma awn apical (36/37), or from a sinus (1/37). Palea 0.9-0.9882-1 length of lemma; 2 -veined (48/48). Palea keels smooth (43), or scaberulous (4), or scabrous (3); eciliate (30), or ciliolate (7), or ciliate (15). Palea surface glabrous (46), or pubescent (2), or pilose (2). Palea apex entire (1/4), or dentate (4/4). Apical sterile florets resembling fertile though underdeveloped.

Flowers

Lodicules 2 (13/13); membranous (13/13). Anthers 3 (30/30). Stigmas 2 (15/15). Ovary pubescent on apex (20/20).

Fruits

Caryopsis with adherent pericarp (23/23); fusiform (1/2), or ellipsoid (1/2); isodiametric (1/1); smooth (1/1); apex unappendaged (2/2). Embryo 0.2 length of caryopsis. Hilum linear (14/14); 0.9 length of caryopsis.

Distribution

Europe (7), or Temperate Asia (39), or Tropical Asia (1), or Australasia (3), or North America (11), or South America (2), or Antarctica (1).