Poaceae
Olyra

Olyra retrorsa Soderstr. & Zuloaga

First published in Smithsonian Contr. Bot. 69: 54 (1989)
This species is accepted
The native range of this species is Brazil (Mato Grosso). It is a herbaceous bamboo and grows primarily in the seasonally dry tropical biome.

Descriptions

Morphology General Habit
Perennial. Culms erect; woody. Culm-internodes thin-walled; distally pubescent. Culm-nodes swollen; brown; glabrous. Leaves cauline. Leaf-sheaths pilose. Leaf-sheath auricles erect. Ligule a ciliolate membrane; 2.5-4 mm long; pubescent on abaxial surface. Leaf-blade base cordate; symmetrical; with a brief petiole-like connection to sheath; petiole 0.2-0.3 cm long; petiole pilose. Leaf-blades drooping; lanceolate; 10.5-13.3 cm long; 27-34 mm wide. Leaf-blade venation parallel. Leaf-blade surface glabrous; hairless except near base. Leaf-blade margins smooth, or scaberulous. Leaf-blade apex acuminate.
Morphology Reproductive morphology Inflorescences
Monoecious; with male and female spikelets in the same inflorescence. Inflorescence a panicle; terminal and axillary. Panicle contracted; oblong; 13.8 cm long; 1-2 cm wide. Primary panicle branches not whorled; bearing 1-4 fertile spikelets on each lower branch; bearing spikelets almost to the base. Panicle branches scabrous. Sexes segregated; on unisexual branches and bisexual branches; with male below. Spikelets solitary. Fertile spikelets pedicelled. Male spikelets sessile and pedicelled; 2 in a cluster. Pedicels (female) linear; angular; ciliate; tip widened.
Morphology Reproductive morphology Inflorescences Spikelets
Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; dorsally compressed; 13.8 mm long; 3.1 mm wide; breaking up at maturity; disarticulating below each fertile floret. Male spikelets distinct from female; 1 flowered; lanceolate; 9-9.7 mm long; glabrous. Male spikelet glumes absent. Male spikelet lemma 3 -veined; awned; with 1-2 mm long awn.
Fertile
Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; dorsally compressed; 13.8 mm long; 3.1 mm wide; breaking up at maturity; disarticulating below each fertile floret.
Morphology Reproductive morphology Inflorescences Bracts Glume
Glumes persistent; similar; exceeding apex of florets; thinner than fertile lemma. Lower glume elliptic; 13.8 mm long; 1.1-1.2 length of upper glume; herbaceous; without keels; 5-7 -veined. Lower glume lateral veins with cross-veins. Lower glume surface scabrous; rough above; glabrous; inner surface pilose. Lower glume apex caudate; muticous. Upper glume elliptic; 11.6-12.8 mm long; 1.4-1.5 length of adjacent fertile lemma; herbaceous; without keels; 5-7 -veined. Upper glume lateral veins with cross-veins. Upper glume surface scabrous; rough above; inner surface pilose. Upper glume apex caudate.
Morphology Reproductive morphology Flowers Florets
Fertile florets female. Fertile lemma lanceolate; dorsally compressed; 8.5-8.7 mm long; 2.9 mm wide; indurate; light brown; without keel; 5 -veined. Lemma surface pitted. Lemma margins involute. Lemma apex acuminate; pubescent. Palea indurate; 2 -veined; without keels. Palea apex pubescent (retrorsely).
Morphology Reproductive morphology Flowers
Lodicules 3. Anthers 3; 3.1 mm long. Stigmas 2.
Morphology Reproductive morphology Fruits
Disseminule comprising a floret.
sex Male
Male spikelets distinct from female; 1 flowered; lanceolate; 9-9.7 mm long; glabrous. Male spikelet glumes absent. Male spikelet lemma 3 -veined; awned; with 1-2 mm long awn.
Distribution
South America: Brazil.
Reference
Olyreae. Sod & Zuol.
[GB]

Extinction risk predictions for the world's flowering plants to support their conservation (2024). Bachman, S.P., Brown, M.J.M., Leão, T.C.C., Lughadha, E.N., Walker, B.E. https://nph.onlinelibrary.wiley.com/doi/full/10.1111/nph.19592

Conservation
Predicted extinction risk: threatened. Confidence: confident
[AERP]

Sources

  • Angiosperm Extinction Risk Predictions v1

    • Angiosperm Threat Predictions
    • http://creativecommons.org/licenses/by/4.0

  • GrassBase - The Online World Grass Flora

    • Clayton, W.D., Vorontsova, M.S., Harman, K.T. and Williamson, H. (2006 onwards). GrassBase - The Online World Grass Flora.
    • http://creativecommons.org/licenses/by-nc-sa/3.0

  • Kew Backbone Distributions

    • The International Plant Names Index and World Checklist of Vascular Plants 2026. Published on the Internet at http://www.ipni.org and https://powo.science.kew.org/
    • © Copyright 2023 World Checklist of Vascular Plants. http://creativecommons.org/licenses/by/3.0

  • Kew Names and Taxonomic Backbone

    • The International Plant Names Index and World Checklist of Vascular Plants 2026. Published on the Internet at http://www.ipni.org and https://powo.science.kew.org/
    • © Copyright 2023 International Plant Names Index and World Checklist of Vascular Plants. http://creativecommons.org/licenses/by/3.0