Poaceae
Themeda

Themeda tremula (Nees ex Steud.) Hack.

First published in A.L.P.P.de Candolle & A.C.P.de Candolle, Monogr. Phan. 6: 667 (1889)
This species is accepted
The native range of this species is India to Bangladesh, Sri Lanka. It is a perennial and grows primarily in the wet tropical biome.

Descriptions

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: not threatened. Confidence: confident
[AERP]

Morphology General Habit
Perennial. Culms decumbent; slender; 15-120 cm long; without nodal roots, or rooting from lower nodes. Ligule a ciliolate membrane. Leaf-blades 8-30 cm long; 3-8 mm wide.
Morphology Reproductive morphology Inflorescences
Synflorescence compound; fasciculate; 5-30 cm long. Inflorescence composed of racemes; terminal and axillary; subtended by a spatheole; enclosed. Spatheole lanceolate; 1-2 cm long; scarious; brown, or grey; without tubercles, or tuberculate; glabrous, or pilose. Racemes 1; single; oblong; bearing few fertile spikelets; bearing 2 fertile spikelets on each. Rhachis fragile at the nodes. Rhachis internodes linear. Spikelets in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels oblong; 0.5 mm long.
Sterile
Basal sterile spikelets well-developed; 4 in number; forming an involucre about the fertile; subsessile; elliptic; 5.5-7.5 mm long; larger than fertile. Basal sterile spikelet glumes tuberculate; pilose, or villous; lower glume muticous. Companion sterile spikelets well-developed; male; lanceolate; 4-6.5 mm long; longer than fertile; separately deciduous. Companion sterile spikelet callus linear. Companion sterile spikelet glumes tuberculate; pilose, or villous. Companion sterile spikelet lemmas 2; enclosed by glumes.
Morphology Reproductive morphology Inflorescences Spikelets
Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; subterete; 3-3.5 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus oblong; bearded; base obtuse; attached obliquely. Spikelet callus hairs red. Basal sterile spikelets well-developed; 4 in number; forming an involucre about the fertile; subsessile; elliptic; 5.5-7.5 mm long; larger than fertile. Basal sterile spikelet glumes tuberculate; pilose, or villous; lower glume muticous. Companion sterile spikelets well-developed; male; lanceolate; 4-6.5 mm long; longer than fertile; separately deciduous. Companion sterile spikelet callus linear. Companion sterile spikelet glumes tuberculate; pilose, or villous. Companion sterile spikelet lemmas 2; enclosed by glumes.
Fertile
Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; subterete; 3-3.5 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus oblong; bearded; base obtuse; attached obliquely. Spikelet callus hairs red.
Morphology Reproductive morphology Inflorescences Bracts Glume
Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume oblong; 1 length of spikelet; coriaceous; without keels. Lower glume surface with a longitudinal median groove; pubescent. Lower glume hairs red. Lower glume apex obtuse. Upper glume oblong.
Morphology Reproductive morphology Flowers Florets
Basal sterile florets barren; without significant palea. Lemma of lower sterile floret lanceolate; hyaline. Fertile lemma linear; hyaline; without keel; 1 -veined. Lemma apex entire; awned; 1 -awned. Principal lemma awn apical; geniculate; 15-35 mm long overall; with twisted column. Column of lemma awn puberulous. Palea absent or minute.
Distribution
Asia-tropical: India.
Reference
Andropogoneae. WDC.
[GB]

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

  • Herbarium Catalogue Specimens

    • 'The Herbarium Catalogue, Royal Botanic Gardens, Kew. Published on the Internet http://www.kew.org/herbcat [accessed on Day Month Year]'. Please enter the date on which you consulted the system.
    • Digital Image © Board of Trustees, RBG Kew http://creativecommons.org/licenses/by/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