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.

Piresiella

HABIT Perennial. Culms 10–15 cm long. Ligule absent. Leaf-blade base with a brief petiole-like connection to sheath. Leaf-blades oblong.

INFLORESCENCE Monoecious; with male and female spikelets in the same inflorescence. Synflorescence on a separate leafless culm. Inflorescence composed of racemes.

Racemes paired; unilateral. Rhachis angular.

Sexes segregated; on unisexual branches; with male conjugate. Spikelets solitary. Fertile spikelets pedicelled. Male spikelets pedicelled. Pedicels filiform, or cuneate.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets elliptic; dorsally compressed; 3.5–4.5 mm long; breaking up at maturity; disarticulating below each fertile floret.

GLUMES Glumes persistent; exceeding apex of florets; thinner than fertile lemma. Lower glume ovate; 1 length of upper glume; herbaceous; without keels; 5 -veined. Lower glume surface without pits. Lower glume apex acute. Upper glume ovate; 1.1 length of adjacent fertile lemma; herbaceous; without keels; 3 -veined. Upper glume apex acuminate.

FLORETS Fertile florets female. Fertile lemma ovate; coriaceous; without keel; wingless. Lemma surface unwrinkled; without grooves; pubescent. Lemma margins involute. Lemma apex acute. Palea 1 length of lemma; coriaceous; 2 -veined. Palea surface pubescent.

MALE Male spikelets distinct from female; lanceolate. Male spikelet glumes absent. Male spikelet lemma muticous.

DISTRIBUTION South America.

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