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.

Olmeca

HABIT Perennial. Rhizomes short (3), or elongated (2); pachymorph. Stolons absent (4), or present (1). Culms erect (1), or geniculately ascending (2), or rambling (1), or scandent (2); 300–795–1500 cm long; woody. Culm-internodes terete. Culm-nodes flush with internodes (1/1); without obvious supra-nodal ridge (1/3), or with distinct supra-nodal ridge (2/3). Lateral branches dendroid. Branch complement one; solitary. Culm-sheaths persistent; without auricles (1/3), or auriculate (2/3). Culm-sheath blade linear (2), or lanceolate (2), or triangular (1). Leaf-sheath auricles absent (3), or erect (1), or falcate (1). Ligule an eciliate membrane (2), or a ciliolate membrane (3). Leaf-blade base without a false petiole (1), or with a brief petiole-like connection to sheath (4). Leaf-blades filiform (1), or linear (4), or lanceolate (3), or oblong (1). Leaf-blade venation without cross veins (3), or with obscure cross veins (1), or with distinct cross veins (1).

INFLORESCENCE Inflorescence a panicle (4/4).

Panicle open (4/4).

Spikelets solitary (4/4). Fertile spikelets pedicelled (4/4).

FERTILE SPIKELETS Spikelets comprising 0–1 basal sterile florets (1/1); 1 fertile florets (1/4), or 2 fertile florets (2/4), or 5 fertile florets (1/4), or 6–8 fertile florets (2/4), or 9–12 fertile florets (1/4); with a barren rhachilla extension (1/4), or with diminished florets at the apex (3/4). Spikelets linear (4/4), or lanceolate (2/4); laterally compressed (2/4), or subterete (2/4); 16.6–25.57–40 mm long; breaking up at maturity (4/4); disarticulating below each fertile floret (4/4). Rhachilla internodes brief up to lowest fertile floret (3/4), or elongated below proximal fertile floret (1/4); definite (4/4); glabrous (1/4), or sparsely hairy (1/4), or pubescent (3/4).

GLUMES Glumes persistent (4/4); shorter than spikelet (4/4); thinner than fertile lemma (2/4), or similar to fertile lemma in texture (2/4). Lower glume lanceolate (4/4); 0.6–0.8167–1 length of upper glume; membranous (2/4), or chartaceous (2/4); without keels (2/4), or 1-keeled (2/4); 1 -veined (2/3), or 2 -veined (1/3), or 3 -veined (2/3). Lower glume lateral veins absent (1/4), or distinct (4/4). Lower glume surface without pits (4/4). Lower glume apex acute (2/3), or acuminate (1/3); muticous (2/4), or mucronate (1/4), or awned (1/4). Upper glume lanceolate (4/4); 0.33–0.6083–0.75 length of adjacent fertile lemma; membranous (2/4), or chartaceous (2/4); without keels (3/4), or 1-keeled (1/4); 5 -veined (3/3), or 6–7 -veined (2/3). Upper glume apex acute (2/3), or acuminate (1/3); muticous (3/4), or awned (1/4); 1 -awned (1/1).

FLORETS Basal sterile florets barren (1/1); with palea (1/1). Lemma of lower sterile floret lanceolate (1/1); 11–13 -veined (1/1); awned (1/1). Fertile lemma lanceolate (3/4), or elliptic (1/4); chartaceous (4/4); without keel (4/4); wingless (4/4); 7–9 -veined (2/4), or 10 -veined (1/4), or 11 -veined (2/4), or 12–13 -veined (1/4). Lemma surface unwrinkled (4/4); without grooves (4/4); glabrous (3/4), or pubescent (1/4). Lemma margins eciliate (2/4), or ciliolate (1/4), or ciliate (1/4). Lemma apex acute (4/4); muticous (2/4), or awned (2/4); 1 -awned (2/2). Palea 0.9–1–1.1 length of lemma; membranous (2/4), or chartaceous (2/4); 2 -veined (1/4), or 4 -veined (2/4), or 5 -veined (1/4), or 6 -veined (2/4). Palea keels eciliate (3/4), or ciliolate (1/4). Palea surface glabrous (1/4), or puberulous (1/4), or pubescent (3/4). Apical sterile florets resembling fertile though underdeveloped (2/3), or distinct from fertile (1/3).

FLOWER Lodicules 3 (4/4); membranous (2/2); ciliate (4/4). Anthers 3 (4/4). Stigmas 2 (4/4), or 3 (1/4). Ovary glabrous (1/1).

FRUIT Caryopsis with adherent pericarp (2/4), or fleshy pericarp (2/4); orbicular (2/2); isodiametric (2/2).

DISTRIBUTION North America, or South America (1).

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