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.

Agropyron

HABIT Perennial. Rhizomes absent (12), or elongated (6). Culms erect (4/8), or geniculately ascending (4/8), or decumbent (1/8); 10–45.19–100 cm long. Culm-nodes swollen (1/1). Lateral branches lacking (4/4). Leaf-sheath auricles absent (12), or falcate (6). Ligule an eciliate membrane (17), or a ciliolate membrane (1). Leaf-blades stiff (2), or firm (16). Leaf-blade midrib conspicuous (1/1).

INFLORESCENCE Inflorescence composed of racemes. Peduncle tipped by a glumaceous appendage (1/1).

Racemes single; linear (13), or lanceolate (1), or oblong (7), or ovate (1); bilateral; bearing few fertile spikelets (4), or many spikelets (17); bearing 3 fertile spikelets on each (1/4), or 4–5 fertile spikelets on each (4/4), or 6–10 fertile spikelets on each (3/4), or 11–13 fertile spikelets on each (1/4). Rhachis flattened (2/2); terminating in a spikelet (17), or barren extension (1); extension bristle-like (1/1). Spikelet packing broadside to rhachis; crowded (4), or contiguous (10), or lax (2), or distant (2); 2 -rowed (1/1). Rhachis internodes linear (3), or oblong (15). Rhachis internode tip flat (1/1).

Spikelets appressed (1), or ascending (10), or spreading (3), or pectinate (6), or deflexed (2); solitary. Fertile spikelets sessile (17), or pedicelled (1). Pedicels oblong (1/1).

FERTILE SPIKELETS Spikelets comprising 2–5–10 fertile florets; with diminished florets at the apex. Spikelets lanceolate (1), or elliptic (1), or oblong (15), or ovate (2); laterally compressed; 7–11.42–20 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes definite; glabrous (14), or pubescent (4). Floret callus glabrous (1/2), or pubescent (1/2).

GLUMES Glumes persistent; shorter than spikelet; similar to fertile lemma in texture (6), or firmer than fertile lemma (12); parallel to lemmas (16), or gaping (2). Lower glume linear (2), or lanceolate (14), or ovate (2); 0.66–0.9444–1 length of upper glume; coriaceous (17/17); without keels (2), or 1-keeled (16); 1 -veined (6/16), or 3 -veined (7/16), or 4 -veined (2/16), or 5 -veined (3/16), or 6 -veined (1/16), or 7 -veined (2/16). Lower glume lateral veins absent (4), or distinct (14); without ribs (13/14), or ribbed (1/14). Lower glume surface smooth (16), or asperulous (3); without pits; glabrous, or pilose (2). Lower glume apex acute (4), or acuminate (13), or attenuate (1), or setaceously attenuate (1); muticous (11), or mucronate (1), or awned (8). Upper glume linear (1/17), or lanceolate (14/17), or ovate (2/17); 0.4–0.7382–1 length of adjacent fertile lemma; coriaceous (17/17); with undifferentiated margins (14), or hyaline margins (1), or membranous margins (1), or scarious margins (2); without keels (2/17), or 1-keeled (15/17); 1 -veined (5/16), or 3 -veined (7/16), or 4 -veined (3/16), or 5 -veined (4/16), or 6 -veined (1/16), or 7 -veined (2/16), or 9 -veined (1/16). Upper glume primary vein eciliate (17), or ciliate (5). Upper glume lateral veins without ribs (13/14), or ribbed (1/14); convergent at apex (4/4). Upper glume surface smooth (16), or asperulous (3); glabrous, or pilose (2). Upper glume apex acute (3/17), or acuminate (13/17), or attenuate (1/17), or setaceously attenuate (1/17); muticous (10/17), or mucronate (1/17), or awned (8/17); 1 -awned (8/8).

FLORETS Fertile lemma lanceolate (6), or elliptic (9), or ovate (4); chartaceous (12), or coriaceous (6); keeled; wingless; 5 -veined (17), or 6–7 -veined (2), or 10–14 -veined (1). Lemma midvein without distinctive roughness (17), or scabrous (1). Lemma surface smooth (16), or asperulous (2); unwrinkled; without grooves; glabrous (11), or puberulous (1), or pubescent (5), or pilose (5), or hirsute (1), or villous (1). Lemma apex acute (12), or acuminate (6); muticous (5), or mucronate (2), or awned (14); 1 -awned (14/14). Principal lemma awn straight (14/15), or hooked (1/15). Palea 1 length of lemma. Palea keels smooth (12), or scaberulous (1), or scabrous (5); eciliate (11), or ciliate (8). Palea surface glabrous (16), or puberulous (1), or pubescent (1). Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2 (7/7); membranous (3/3); glabrous (6/7), or ciliate (1/7). Anthers 3 (9/9). Stigmas 2 (3/3). Ovary unappendaged (9), or with a fleshy appendage below style insertion (9); pubescent on apex (14/14).

FRUIT Caryopsis with adherent pericarp (17/17); linear (1/7), or ellipsoid (1/7), or oblong (5/7); apex fleshy (9/9). Embryo 0.2 length of caryopsis. Hilum linear (11/11); 0.75–0.9792–1 length of caryopsis.

DISTRIBUTION Europe (6), or Africa (1), or Temperate Asia (9), or Tropical Asia (4), or Australasia (4), or North America (3).

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