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.

Hordeum

HABIT Annual (10), or perennial (27). Rhizomes absent, or short (1). Culms erect (19/24), or geniculately ascending (14/24); slender (1/1); 3–49.84–150 cm long. Leaf-sheath auricles absent (25), or falcate (17). Ligule an eciliate membrane (34), or a ciliolate membrane (2). Leaf-blades filiform (1), or linear (35); stiff (2), or firm (34).

INFLORESCENCE Inflorescence composed of racemes; subtended by an unspecialized leaf-sheath (35), or an inflated leaf-sheath (1); exserted, or embraced at base by subtending leaf (7).

Racemes single; erect (1), or ascending (35); linear (35), or oblong (3), or ovate (1); bilateral; bearing 20–44 fertile spikelets on each (1/2), or 45 fertile spikelets on each (2/2). Rhachis tough (4), or fragile at the nodes (33); wingless (33), or narrowly winged (3); flattened. Spikelet packing broadside to rhachis; 2 -rowed (2/4), or 6 -rowed (2/4). Rhachis internodes oblong (30), or cuneate (6); falling with spikelet above (33/33).

Spikelets in threes. Fertile spikelets sessile, or sessile and pedicelled (1); 1 in the cluster (34), or 3 in the cluster (3). Companion sterile spikelets sessile (2/34), or pedicelled (33/34); 0 in the cluster (1/34), or 2 in the cluster (34/34). Pedicels oblong (32/32).

STERILE SPIKELETS Companion sterile spikelets absent (3), or well-developed (34); persistent (3/34), or deciduous with the fertile (32/34). Companion sterile spikelet glumes awned (2/2).

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension (14), or with a barren rhachilla extension (24), or with diminished florets at the apex (2). Spikelets lanceolate (34), or ovate (1), or cuneate (1); dorsally compressed; 4–10.58–55 mm long; persistent on plant (3), or falling entire (33), or breaking up at maturity (1); deciduous with accessory branch structures (33/33); disarticulating below each fertile floret (1/1).

GLUMES Glumes collateral; shorter than spikelet (9/21), or reaching apex of florets (4/21), or exceeding apex of florets (11/21); parallel to lemmas (10), or recurved at apex (1), or gaping (25). Lower glume subulate (23), or linear (7), or lanceolate (7); 1 length of upper glume; coriaceous (12/12); 2–3 -veined (1/1). Lower glume lateral veins obscure (1), or distinct (35). Lower glume surface smooth (25), or scabrous (11); without pits; glabrous (31), or puberulous (1), or pubescent (2), or hispidulous (2). Lower glume apex acuminate (3/7), or setaceously attenuate (4/7); muticous (7/13), or awned (6/13). Upper glume subulate (23), or linear (7), or lanceolate (7); 0.3–0.7917–1.7 length of adjacent fertile lemma; coriaceous (12/12); 2–3 -veined (1/1). Upper glume surface smooth (27), or scabrous (9); glabrous (31), or puberulous (1), or pubescent (2), or hispidulous (2). Upper glume apex acuminate (3/7), or setaceously attenuate (4/7); muticous (7/13), or awned (6/13); 1 -awned (6/6).

FLORETS Fertile lemma lanceolate (30), or elliptic (4), or ovate (3); coriaceous; without keel; wingless; 5 -veined (35), or 7–9 -veined (1). Lemma lateral veins obscure (3/4), or prominent (1/4). Lemma surface smooth (24), or asperulous (2), or scaberulous (5), or scabrous (7); unwrinkled; without grooves; glabrous (30), or puberulous (5), or pubescent (5), or pilose (1). Lemma apex entire (35), or dentate (1); 3 -fid (1/1); acuminate (34/35), or attenuate (1/35); without appendage (35), or with a trilobate appendage (1); muticous (4), or awned (35); 1 -awned (35/35). Principal lemma awn straight (34/35), or curved (1/35). Palea 1 length of lemma. Palea keels eciliate (35), or ciliate (1). Apical sterile florets rudimentary (2/2).

FLOWER Lodicules 2 (13/13); membranous (1/1); glabrous (4/13), or ciliate (10/13); obtuse (1/4), or acute (4/4). Anthers 3. Ovary pubescent on apex.

FRUIT Caryopsis with adherent pericarp; ellipsoid (4/6), or ovoid (2/6). Embryo 0.2 length of caryopsis. Hilum linear; 1 length of caryopsis.

DISTRIBUTION Europe (10), or Africa (9), or Temperate Asia (14), or Tropical Asia (8), or Australasia (6), or Pacific (3), or North America (10), or South America (25), or Antarctica (3).

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