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 bahiensis

HABIT Perennial; caespitose. Culms erect, or geniculately ascending; 20–50 cm long. Culm-internodes hollow. Lateral branches lacking. Leaves cauline; 5–9 per branch. Leaf-sheaths outer margin hairy. Ligule a ciliolate membrane; 0.3–0.5 mm long. Leaf-blade base asymmetrical; with a brief petiole-like connection to sheath; petiole 0.1–0.2 cm long; petiole pilose. Leaf-blades drooping; lanceolate, or ovate; 5.5–7 cm long; 21–26 mm wide. Leaf-blade surface glabrous. Leaf-blade margins scabrous. Leaf-blade apex acuminate.

INFLORESCENCE Monoecious; with male and female spikelets in the same inflorescence (or some all male). Inflorescence a panicle; comprising 1 fertile spikelets (and 8–10 male); terminal and axillary. Axillary inflorescences present throughout the plant.

Panicle open; linear; 1.4–2.5 cm long; bearing few spikelets. Panicle branches hispid.

Sexes segregated; on unisexual branches; with male below. Spikelets solitary. Fertile spikelets pedicelled. Male spikelets pedicelled; 2–3 in a cluster. Pedicels clavate; ciliate.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets elliptic; dorsally compressed; 13–14.5 mm long; 3 mm wide; breaking up at maturity; disarticulating below each fertile floret. Floret callus brief; pubescent; truncate.

GLUMES Glumes deciduous; similar; exceeding apex of florets; thinner than fertile lemma. Lower glume elliptic; 13–14.5 mm long; 1.1 length of upper glume; membranous; pallid; without keels; 9 -veined. Lower glume lateral veins with cross-veins. Lower glume surface scabrous; rough above. Lower glume apex attenuate. Upper glume elliptic; 12–13 mm long; 1.6 length of adjacent fertile lemma; membranous; pallid; without keels; 7–9 -veined. Upper glume lateral veins with cross-veins. Upper glume surface scabrous; rough above. Upper glume apex acute, or acuminate.

FLORETS Fertile florets female. Fertile lemma elliptic; dorsally compressed; 7.3–8.1 mm long; 2.5–2.9 mm wide; indurate; yellow, or light brown; without keel; 5 -veined. Lemma surface pubescent; hairy above. Lemma margins pubescent. Lemma apex acute. Palea indurate. Palea apex undifferentiated, or papillose.

FLOWER Lodicules 3; 0.4 mm long; membranous. Anthers 3; 2 mm long. Stigmas 2.

FRUIT Caryopsis light brown. Hilum linear; 1 length of caryopsis.

MALE Male spikelets distinct from female; 1 flowered; elliptic; 4–4.5 mm long. Male spikelet glumes absent. Male spikelet lemma 3 -veined.

DISTRIBUTION South America: Brazil.

NOTES Olyreae. Soderstrom.

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