GrassBase - The Online World Grass Flora


W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Olyra humilis

HABIT Perennial; caespitose. Rhizomes short, or elongated. Culms erect, or geniculately ascending; 25–100 cm long; woody. Culm-internodes hollow; distally glabrous, or hispid. Culm-nodes swollen; brown; glabrous. Leaves cauline. Leaf-sheaths ribbed; glabrous on surface, or pilose; outer margin hairy. Ligule a ciliolate membrane; 0.4 mm long. Leaf-blade base broadly rounded; asymmetrical; with a brief petiole-like connection to sheath; petiole 0.2 cm long; petiole pilose. Leaf-blades lanceolate, or ovate; 4.3–11.5 cm long; 10–22 mm wide; glaucous. Leaf-blade venation parallel. Leaf-blade surface smooth, or scaberulous; rough adaxially; glabrous. Leaf-blade margins scabrous.

INFLORESCENCE Monoecious; with male and female spikelets in the same inflorescence. Inflorescence a panicle; terminal and axillary.

Panicle open; pyramidal; 4–9 cm long; 1–5.5 cm wide. Primary panicle branches ascending; whorled at lower nodes; bearing 1 fertile spikelets on each lower branch; bearing spikelets almost to the base. Panicle branches scabrous.

Sexes segregated; on bisexual branches; with male below. Spikelets solitary. Fertile spikelets pedicelled. Male spikelets pedicelled; 2 in a cluster. Pedicels (female) clavate; angular; smooth; glabrous.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; dorsally compressed; 14–21 mm long; breaking up at maturity; disarticulating below each fertile floret.

GLUMES Glumes persistent; similar; exceeding apex of florets; thinner than fertile lemma. Lower glume elliptic; 14–21 mm long; 1.3–1.8 length of upper glume; membranous; without keels; 5–7 -veined. Lower glume lateral veins with cross-veins. Lower glume surface smooth, or asperulous; inner surface glabrous, or pilose. Lower glume apex acuminate; awned; 1 -awned. Lower glume awn 4–10 mm long. Upper glume elliptic; 11–11.5 mm long; 1.2–1.8 length of adjacent fertile lemma; membranous; without keels; 5–7 -veined. Upper glume lateral veins with cross-veins. Upper glume apex acuminate to setaceously attenuate.

FLORETS Fertile florets female. Fertile lemma elliptic; dorsally compressed; 6–9.8 mm long; indurate; pallid; shiny; without keel; 5 -veined. Lemma surface pilose; hairy above and below. Lemma margins involute. Lemma apex acute. Palea indurate; 2 -veined; without keels. Palea apex pubescent.

FLOWER Lodicules 3. Anthers 3; 3.6–5.2 mm long. Stigmas 2.

FRUIT Caryopsis with adherent pericarp; ellipsoid; 5 mm long; light brown. Hilum linear; 1 length of caryopsis. Disseminule comprising a floret.

MALE Male spikelets distinct from female; 1 flowered; lanceolate; 8.5–11 mm long; glabrous. Male spikelet glumes absent. Male spikelet lemma 3 -veined; awned; with 2–2.5 mm long awn.

DISTRIBUTION South America: Brazil and southern South America.

NOTES Olyreae. Sod & Zuol.

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