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 recta

HABIT Perennial; culms solitary. Rhizomes elongated; pachymorph. Culms geniculately ascending; 1000–1500 cm long; 45–50 mm diam.; woody. Culm-internodes terete; with small lumen; distally pubescent. Culm-nodes with distinct supra-nodal ridge. Lateral branches dendroid. Bud complement 1. Branch complement one; solitary. Culm-sheaths persistent; hispid; with dark brown hairs; setose on shoulders. Culm-sheath ligule 4–5 mm high. Culm-sheath blade linear; erect (deciduous); 30–35 cm long; pubescent. Leaves cauline; 8–12 per branch. Leaf-sheaths outer margin hairy. Leaf-sheath oral hairs setose; erect; 30–40 mm long. Ligule a ciliolate membrane; 1–2 mm long. Leaf-blades 20–30 cm long; 10–28 mm wide. Leaf-blade surface pilose; sparsely hairy. Leaf-blade margins scaberulous.

INFLORESCENCE Inflorescence a panicle.

Panicle open; lanceolate; 40–60 cm long.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels 10–20 mm long.

FERTILE SPIKELETS Spikelets comprising 5–8 fertile florets; with diminished florets at the apex. Spikelets linear; laterally compressed; 20–30 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes eventually visible between lemmas; glabrous, or pubescent.

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume lanceolate; 4.1 mm long; 0.9–1 length of upper glume; chartaceous; 1-keeled. Upper glume lanceolate; 4.7 mm long; chartaceous; without keels.

FLORETS Fertile lemma lanceolate; 8 mm long; chartaceous; without keel; 7–11 -veined. Lemma apex acute. Palea linear; 1.1 length of lemma; chartaceous; 6 -veined. Palea surface pubescent; hairy on back. Palea apex pubescent. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 3; oblong; 2 mm long; membranous; veined; ciliate. Anthers 3; 5.3–6 mm long. Stigmas 2.

FRUIT Caryopsis with fleshy pericarp; orbicular; isodiametric; 25 mm long. Endosperm evanescent.

DISTRIBUTION North America: Mexico.

NOTES Bambuseae. WDC.

Please cite this publication as detailed in How to Cite Version: 3rd February 2016.