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.

Piresia leptophylla

HABIT Perennial; caespitose. Culms 20–35 cm long; wiry. Culm-nodes pubescent. Leaves cauline; 6–12 per branch. Ligule an eciliate membrane. Leaf-blade base with a brief petiole-like connection to sheath. Leaf-blades lanceolate; 5–6 cm long; 4–7 mm wide. Leaf-blade apex acute.

INFLORESCENCE Monoecious; with male and female spikelets in the same inflorescence. Synflorescence on the same culm as leaves (rarely), or on a separate leafless culm. Inflorescence composed of racemes.

Racemes 1; single; 3.5–4 cm long; bearing few fertile spikelets; bearing 2–3 fertile spikelets on each (and 2–5 male).

Sexes mixed. Spikelets solitary, or in pairs. Fertile spikelets pedicelled; 1 in the cluster. Male spikelets sessile; 1 in a cluster. Pedicels cuneate.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets ovate; dorsally compressed; 5–7 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; 5–7 mm long; 1 length of upper glume; herbaceous; without keels; 5 -veined. Lower glume lateral veins with cross-veins. Lower glume apex acuminate. Upper glume ovate; 5–7 mm long; 1.2 length of adjacent fertile lemma; herbaceous; without keels; 5 -veined. Upper glume lateral veins with cross-veins. Upper glume apex acuminate.

FLORETS Fertile florets female. Fertile lemma ovate; 5 mm long; indurate; pallid and dark brown; mottled with last colour; shiny; without keel; 5 -veined. Lemma lateral veins with cross-veins. Lemma surface pubescent. Lemma apex truncate. Palea indurate; 2 -veined.

FLOWER Anthers 3.

FRUIT Caryopsis with adherent pericarp; ovoid; 4 mm long. Embryo 0.2 length of caryopsis. Hilum linear; 1 length of caryopsis.

MALE Male spikelets distinct from female; 1 flowered; separately deciduous; lanceolate; 4 mm long; glabrous. Male spikelet glumes absent. Male spikelet lemma 3 -veined; muticous.

DISTRIBUTION South America: western South America and Brazil.

NOTES Olyreae. WDC.

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