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.

Raddia guianensis

HABIT Perennial; caespitose. Culms geniculately ascending; 20–45 cm long; wiry. Leaves cauline; 12–24 per branch; distichous. Leaf-sheaths longer than adjacent culm internode. Ligule an eciliate membrane. Leaf-blade base broadly rounded; with a brief petiole-like connection to sheath; petiole pubescent. Leaf-blades spreading; oblong; 2–3.5 cm long; 4–8 mm wide. Leaf-blade apex obtuse; apiculate.

INFLORESCENCE Monoecious; with male and female spikelets in different inflorescences. Inflorescence composed of racemes; axillary; embraced at base by subtending leaf.

Racemes 1; single; bearing few fertile spikelets; bearing 2–5 fertile spikelets on each. Rhachis angular.

Spikelets solitary. Fertile spikelets pedicelled. Male spikelets pedicelled. Pedicels filiform (male), or cuneate (female).

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; dorsally compressed; 8 mm long; breaking up at maturity; disarticulating below each fertile floret.

GLUMES Glumes deciduous; similar; exceeding apex of florets; thinner than fertile lemma. Lower glume ovate; 8 mm long; 1 length of upper glume; chartaceous; firmer on margins; without keels; 5 -veined. Lower glume surface glabrous. Lower glume apex setaceously attenuate. Upper glume ovate; 8 mm long; 1.6 length of adjacent fertile lemma; chartaceous; with cartilaginous margins; without keels; 5 -veined. Upper glume apex setaceously attenuate.

FLORETS Fertile florets female. Fertile lemma lanceolate; 5 mm long; coriaceous; without keel; 3 -veined. Lemma margins involute. Lemma apex acuminate. Palea coriaceous; 2 -veined.

FLOWER Lodicules 3. Anthers 3.

MALE Male inflorescence axillary; unlike female; of few spikelets (5–8). Male spikelets distinct from female; 1 flowered; separately deciduous; linear, or lanceolate; 5–6 mm long; glabrous. Male spikelet glumes absent. Male spikelet lemma 3 -veined.

DISTRIBUTION South America: Caribbean, northern South America, and Brazil.

NOTES Olyreae. WDC.

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