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.

Arberella

HABIT Perennial. Culms erect (5), or geniculately ascending (6); 15–35.14–60 cm long; firm (6), or wiry (1). Culm-internodes terete (1/1). Culm-nodes constricted (2/2). Lateral branches lacking (6/6). Ligule a ciliolate membrane. Leaf-blade base with a brief petiole-like connection to sheath. Leaf-blades linear (1), or lanceolate (6), or elliptic (1), or oblong (1), or ovate (3).

INFLORESCENCE Monoecious; with male and female spikelets in the same inflorescence. Inflorescence a panicle; terminal and axillary; exserted (6), or embraced at base by subtending leaf (1).

Panicle open (6), or contracted (1).

Sexes segregated; on unisexual branches; with male below. Spikelets solitary. Fertile spikelets pedicelled. Male spikelets pedicelled; 1 in a cluster (1/5), or 2 in a cluster (5/5), or 3 in a cluster (1/5). Pedicels filiform (1/6), or linear (4/6), or clavate (6/6).

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate (6), or elliptic (1), or obovate (1); dorsally compressed; 7.055–13.19–22 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus brief (1), or evident (6); glabrous (1/4), or pubescent (2/4), or woolly (1/4); truncate.

GLUMES Glumes deciduous; exceeding apex of florets; thinner than fertile lemma; incurved at apex (1), or parallel to lemmas (6). Lower glume lanceolate (2), or elliptic (5); 1–1.05–1.1 length of upper glume; membranous (6), or chartaceous (1); without keels; 5–6 -veined (1), or 7 -veined (2), or 8 -veined (1), or 9 -veined (4), or 10 -veined (1), or 11 -veined (2). Lower glume surface smooth (5), or scabrous (2); without pits. Lower glume apex acuminate (2), or attenuate (4), or caudate (1); muticous (6), or awned (1). Upper glume lanceolate (2), or elliptic (5); 1.3–1.521–1.6 length of adjacent fertile lemma; membranous (6), or chartaceous (1); without keels; 5–6 -veined (2), or 7 -veined (3), or 8 -veined (2), or 9 -veined (4), or 10 -veined (1). Upper glume lateral veins with cross-veins (5/5). Upper glume surface smooth (6), or scabrous (1). Upper glume apex acute (1), or acuminate (4), or attenuate (2), or caudate (1).

FLORETS Fertile florets female. Fertile lemma lanceolate (2), or elliptic (5), or oblong (1), or ovate (2); dorsally compressed; indurate; without keel; wingless; 5 -veined (4/5), or 7 -veined (1/5). Lemma surface unwrinkled; without grooves; pubescent (6), or pilose (1). Lemma margins eciliate (1), or ciliate (1), or pubescent (5). Lemma apex acute (5), or acuminate (1), or apiculate (1). Palea 1 length of lemma; indurate; 4 -veined (1/4), or 6 -veined (1/4), or 8 -veined (1/4), or 9 -veined (2/4), or 10 -veined (1/4). Palea surface glabrous (5), or puberulous (1), or pubescent (2).

FLOWER Lodicules 3; membranous; truncate (1/1). Anthers 3. Stigmas 2; plumose (6), or sparsely hairy (1).

FRUIT Hilum linear (1/1); 1 length of caryopsis.

MALE Male spikelets distinct from female; linear (4), or lanceolate (6), or elliptic (1). Male spikelet glumes absent. Male spikelet lemma awned (2/2).

DISTRIBUTION South America.

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