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.

Nassella

HABIT Perennial. Rhizomes absent (109), or short (12), or elongated (2). Culms erect (82/86), or geniculately ascending (20/86), or decumbent (3/86); robust (1/16), or slender (14/16), or weak (1/16); 5–54.29–175 cm long; without nodal roots (1/1). Culm-internodes terete (3/3). Culm-nodes constricted (3/12), or flush with internodes (4/12), or swollen (5/12). Lateral branches lacking (44/48), or sparse (1/48), or ample (4/48). Leaf-sheath auricles absent (119), or erect (1). Ligule an eciliate membrane (113), or a ciliolate membrane (5), or a fringe of hairs (2), or absent (1). Leaf-blades persistent (118), or deciduous at the ligule (3); aciculate (2), or filiform (41), or linear (82); herbaceous (119), or coriaceous (1); stiff (16), or firm (103), or flaccid (1). Leaf-blade apex muticous (107), or pungent (13).

INFLORESCENCE Inflorescence a panicle; terminal, or terminal and axillary (3); not deciduous as a whole (118), or deciduous as a whole (2); subtended by an unspecialized leaf-sheath (113), or an inflated leaf-sheath (7); exserted (94), or embraced at base by subtending leaf (40). Peduncle persistent (119), or disarticulating (1).

Panicle open (100), or contracted (25), or spiciform (1). Primary panicle branches not whorled (117), or whorled at most nodes (3).

Spikelets appressed (2/2); solitary. Fertile spikelets pedicelled. Pedicels filiform (2/2); tip widened (2/2).

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension (119/119). Spikelets linear (1), or lanceolate (109), or elliptic (1), or oblong (1), or ovate (7), or obovate (1); laterally compressed (15), or subterete (105); 2.5–11.91–49 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus brief (28), or evident (39), or elongated (56); glabrous (5/114), or sparsely hairy (1/114), or pubescent (83/114), or pilose (20/114), or bearded (6/114); obtuse (23), or acute (47), or pungent (50).

GLUMES Glumes persistent (119/119); shorter than spikelet (2), or reaching apex of florets (2), or exceeding apex of florets (119); thinner than fertile lemma; parallel to lemmas (119), or gaping (1). Lower glume linear (7), or lanceolate (108), or elliptic (1), or oblong (2), or ovate (3); 0.75–1.068–1.7 length of upper glume; hyaline (25), or membranous (95); without keels (105), or 1-keeled (15); 1 -veined (7/105), or 2 -veined (4/105), or 3 -veined (97/105), or 4 -veined (16/105), or 5 -veined (18/105), or 6 -veined (1/105). Lower glume lateral veins absent (7), or obscure (2), or distinct (115). Lower glume surface smooth (106), or asperulous (11), or scabrous (7); without pits; glabrous (116), or puberulous (3), or pubescent (3), or pilose (1). Lower glume apex obtuse (1/119), or acute (10/119), or acuminate (65/119), or attenuate (23/119), or setaceously attenuate (22/119), or cuspidate (1/119); muticous (114), or mucronate (1), or awned (5). Upper glume linear (6), or lanceolate (109), or elliptic (1), or oblong (2), or ovate (3); 1.1–1.983–4 length of adjacent fertile lemma; hyaline (28), or membranous (92); without keels (109), or 1-keeled (11); 1 -veined (3/103), or 2 -veined (2/103), or 3 -veined (86/103), or 4 -veined (15/103), or 5 -veined (30/103), or 6 -veined (1/103). Upper glume primary vein eciliate (118), or ciliolate (2), or ciliate (2). Upper glume surface smooth (106), or asperulous (11), or scabrous (7); glabrous (116), or puberulous (2), or pubescent (3), or pilose (1). Upper glume apex obtuse (1), or acute (11), or acuminate (67), or attenuate (22), or setaceously attenuate (21), or cuspidate (1); muticous (117), or mucronate (1), or awned (2); 1 -awned (2/2).

FLORETS Fertile lemma linear (26), or lanceolate (54), or elliptic (11), or oblong (11), or ovate (1), or orbicular (1), or oblate (1), or obovate (16); laterally compressed (21), or subterete (99); not gibbous (107), or gibbous (13); membranous (1), or chartaceous (12), or coriaceous (109); without keel (109), or keeled (11); wingless; 5 -veined (101/101). Lemma midvein eciliate (93), or ciliolate (5), or ciliate (11), or pubescent (12). Lemma lateral veins prominent (1/1). Lemma surface smooth (55), or granulose (1), or asperulous (13), or scaberulous (6), or scabrous (2), or papillose (39), or tuberculate (6), or striate (1), or punctate (1); unwrinkled (119), or rugulose (1); without grooves; glabrous (50), or puberulous (8), or pubescent (43), or pilose (20), or villous (1), or woolly (1); hairy on back (59/72), or on veins (12/72), or in lines (1/72); without hair tufts (116), or with conspicuous apical hairs (4). Lemma margins convolute; covering most of palea; eciliate (115), or ciliate (4), or pubescent (1). Lemma apex entire (118), or dentate (2); 2 -fid (2/2); emarginate (1/13), or truncate (5/13), or obtuse (7/13), or acute (1/13); without appendage (33), or with an annular corona (2), or with a membranous corona (57), or surmounted by a ring of hairs (65), or with a short cylindrical neck (3); awned; 1 -awned. Principal lemma awn median (101), or eccentric (20); apical (119), or from a sinus (1); curved (1), or flexuous (8), or geniculate (34), or bigeniculate (92); limb glabrous (118), or ciliate (1), or hirsute (1). Column of lemma awn glabrous (56/115), or hispidulous (5/115), or puberulous (16/115), or pubescent (29/115), or ciliate (7/115), or hirtellous (1/115), or hirsute (1/115), or plumose (1/115). Palea present (119), or absent or minute (1); 0.1–0.4042–1 length of lemma; hyaline (7/119), or membranous (112/119); 0 -veined (102/110), or 2 -veined (8/110); without keels (117/119), or 2-keeled (2/119). Palea surface glabrous (118/119), or pubescent (1/119), or pilose (1/119). Palea apex erose (1/1).

FLOWER Lodicules 2 (67/78), or 3 (16/78); membranous (2/2). Anthers 1 (7/109), or 3 (105/109). Stigmas 2 (93/93). Ovary glabrous (75/76), or pubescent on apex (1/76).

FRUIT Caryopsis with adherent pericarp (108/108); linear (11/82), or fusiform (53/82), or ellipsoid (8/82), or oblong (4/82), or obovoid (10/82); laterally compressed (1/1); trigonous (1/1). Embryo 0.2–0.275–0.35 length of caryopsis. Hilum linear (97/97); 0.5–0.7617–1 length of caryopsis.

CLEISTOGENES AND VIVIPARY Cleistogenes absent (117), or present (3); in upper sheaths (1/3), or in lower sheaths (2/3).

DISTRIBUTION Europe (1), or Africa (3), or Temperate Asia (1), or Australasia (7), or Pacific (1), or North America (10), or South America (113).

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