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.

Agrostis

HABIT Annual (66), or perennial (183). Rhizomes absent (205), or short (21), or elongated (22). Stolons absent (233), or present (13). Culms erect (138/184), or geniculately ascending (91/184), or decumbent (22/184), or prostrate (1/184); slender (23/30), or weak (7/30); 1–37.94–150 cm long; without nodal roots (5/14), or rooting from lower nodes (14/14). Culm-internodes terete (5/6), or elliptical in section (1/6). Lateral branches lacking (50/53), or sparse (6/53), or ample (1/53). Leaves differentiated into sheath and blade (239), or without demarcation between sheath and blade (1). Leaf-sheaths open for most of their length (1/1). Ligule an eciliate membrane (239), or a ciliolate membrane (1). Leaf-blade base without a false petiole (239), or with a false petiole (1). Leaf-blades aciculate (4), or filiform (39), or linear (200), or lanceolate (1); herbaceous (238), or coriaceous (2); stiff (14), or firm (216), or flaccid (10).

INFLORESCENCE Inflorescence a panicle (239), or a panicle with branches tipped by a raceme (1), or comprising only a few spikelets (1); not deciduous as a whole (221), or deciduous as a whole (19); exserted (227), or embraced at base by subtending leaf (16). Peduncle persistent (224), or fracturing (16).

Panicle open (176/239), or contracted (57/239), or spiciform (19/239), or capitate (1/239). Primary panicle branches not whorled (176/239), or whorled at lower nodes (16/239), or whorled at most nodes (48/239).

Spikelets appressed (4/7), or ascending (1/7), or spreading (2/7); solitary. Fertile spikelets pedicelled. Pedicels filiform (30/50), or linear (1/50), or clavate (19/50); tip rectangular (2/19), or widened (17/19).

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension (192/236), or with a barren rhachilla extension (58/236), or with diminished florets at the apex (1/236). Spikelets linear (1/239), or lanceolate (90/239), or elliptic (142/239), or oblong (27/239), or cuneate (3/239); laterally compressed; 0.6–2.986–7.5 mm long; breaking up at maturity; disarticulating below each fertile floret. Spikelet callus glabrous (4/4); base obtuse (1/1). Floret callus glabrous (63/198), or sparsely hairy (15/198), or pubescent (97/198), or pilose (26/198), or bearded (8/198).

GLUMES Glumes persistent (239), or deciduous (1); shorter than spikelet (1), or reaching apex of florets (14), or exceeding apex of florets (229); thinner than fertile lemma (1), or firmer than fertile lemma (239); parallel to lemmas (65), or gaping (176). Lower glume linear (1), or lanceolate (216), or elliptic (16), or oblong (11), or ovate (7); 0.5–1.022–1.5 length of upper glume; membranous (237), or chartaceous (1), or herbaceous (1), or scarious (1), or cartilaginous (1); without keels (2/239), or 1-keeled (237/239); 1 -veined (226/235), or 2 -veined (5/235), or 3 -veined (13/235). Lower glume lateral veins absent (225), or obscure (5), or distinct (14). Lower glume surface smooth (204), or asperulous (37), or scabrous (14); without pits; glabrous (238), or puberulous (1), or hispidulous (1). Lower glume apex entire (239), or erose (1); truncate (1), or obtuse (7), or acute (185), or acuminate (60), or caudate (1); muticous (236), or mucronate (4), or awned (4). Upper glume linear (1), or lanceolate (217), or elliptic (16), or oblong (12), or ovate (6); 0.8–1.415–5 length of adjacent fertile lemma; membranous (237), or chartaceous (2), or herbaceous (1), or scarious (1); with undifferentiated margins (226), or hyaline margins (14); without keels (2/239), or 1-keeled (237/239); 1 -veined (215/234), or 2 -veined (9/234), or 3 -veined (28/234). Upper glume surface smooth (203), or asperulous (34), or scabrous (17), or papillose (1); glabrous (239), or hispidulous (1). Upper glume apex entire (239), or erose (1); truncate (1/239), or obtuse (6/239), or acute (186/239), or acuminate (61/239), or caudate (1/239); muticous (235), or mucronate (5), or awned (4); 1 -awned (4/4).

FLORETS Fertile lemma lanceolate (21), or elliptic (91), or oblong (105), or ovate (51); dorsally compressed (1/1); hyaline (223), or membranous (9), or chartaceous (2), or cartilaginous (6); without keel; wingless; 3 -veined (14/230), or 4 -veined (12/230), or 5 -veined (224/230). Lemma midvein extending to apex (1/1). Lemma lateral veins obscure (25/30), or distinct (1/30), or prominent (5/30); excurrent (59/119), or extending close to apex (65/119). Lemma surface smooth (218), or asperulous (8), or scaberulous (18), or scabrous (1); unwrinkled; without grooves; glabrous (188), or puberulous (9), or pubescent (24), or pilose (31), or villous (1), or hispidulous (1). Lemma margins eciliate (238), or ciliate (2). Lemma apex entire (107), or erose (64), or dentate (72), or lobed (2); 2 -fid (16/72), or 3 -fid (2/72), or 4 -fid (55/72), or 5 -fid (3/72); incised 0.15–0.3–0.5 of lemma length; emarginate (2/195), or truncate (169/195), or obtuse (29/195), or acute (6/195); muticous (105), or mucronate (14), or awned (164); 1 -awned (137/146), or 2 -awned (1/146), or 3 -awned (5/146), or 5 -awned (3/146). Principal lemma awn apical (4/173), or subapical (15/173), or dorsal (154/173); straight (74/173), or curved (12/173), or flexuous (1/173), or geniculate (102/173). Lateral lemma awns shorter than principal (1/1). Palea present (180), or absent or minute (66); 0–0.5529–1 length of lemma; hyaline (173/180), or membranous (7/180); 0 -veined (11/77), or 1 -veined (2/77), or 2 -veined (68/77); without keels (2/180), or 2-keeled (179/180). Palea keels smooth (177/179), or scaberulous (1/179), or scabrous (1/179). Palea apex entire (3/8), or erose (1/8), or dentate (6/8); muticous (174/180), or with excurrent keel veins (6/180). Apical sterile florets 1 in number (1/1); barren (1/1); lanceolate (1/1). Apical sterile lemmas awned (1/1).

FLOWER Lodicules absent (1/205), or 2 (204/205); membranous (203/203); acute (8/8). Anthers 1 (1/231), or 3 (230/231). Stigmas 2 (20/20). Ovary glabrous (1/1).

FRUIT Caryopsis with adherent pericarp (215/215); lanceolate (1/27), or fusiform (2/27), or ellipsoid (14/27), or oblong (6/27), or ovoid (5/27), or obovoid (1/27); isodiametric (5/6), or dorsally compressed (1/6); biconvex (5/5); smooth (5/5); apex unappendaged (8/8). Embryo 0.2–0.2305–0.33 length of caryopsis. Hilum punctiform (2/174), or elliptic (4/174), or linear (168/174); 0.9 length of caryopsis.

DISTRIBUTION Europe (27), or Africa (53), or Temperate Asia (47), or Tropical Asia (27), or Australasia (54), or Pacific (7), or North America (39), or South America (62), or Antarctica (13).

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