Hyparrhenia tamba (Hochst. ex Steud.) Andersson ex Stapf

First published in D.Oliver & auct. suc. (eds.), Fl. Trop. Afr. 9: 336 (1919)
This species is accepted
The native range of this species is Eritrea to S. Africa. It is a perennial and grows primarily in the seasonally dry tropical biome.

Descriptions

Morphology General Habit
Perennial; caespitose. Butt sheaths pubescent. Culms erect; robust; 100-200 cm long; 2-4 mm diam. Leaves cauline. Ligule an eciliate membrane; 2-4 mm long. Leaf-blades 20-40 cm long; 3-7 mm wide; stiff; glaucous. Leaf-blade surface scaberulous; glabrous. Leaf-blade margins scabrous.
Morphology Reproductive morphology Inflorescences
Synflorescence compound; paniculate; 30-60 cm long. Inflorescence composed of racemes; terminal and axillary; subtended by a spatheole; embraced at base by subtending leaf, or enclosed. Spatheole lanceolate; 2.6-4 cm long; membranous; brown; glabrous, or pilose. Peduncle nodding; 2-3 cm long; pilose above. Racemes 2; paired; deflexed; 1.5 cm long; bearing few fertile spikelets; bearing 2-4 fertile spikelets on each. Rhachis fragile at the nodes; ciliate on margins. Rhachis hairs white. Rhachis internodes linear; 2-3 mm long. Rhachis internode tip oblique; flat. Raceme-bases flattened; subequal; 0.5-1 mm long; stiffly setose; scariously rimmed; with 0.2-0.5 mm long appendage. Spikelets appressed; in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels linear; flattened; ciliate; tip oblique.
Morphology Reproductive morphology Inflorescences Spikelets
Basal sterile spikelets well-developed; on lower raceme 2 in number; 0 in upper raceme; lanceolate; 8-9 mm long; larger than fertile. Basal sterile spikelet glumes villous; smooth on margins; lower glume muticous. Companion sterile spikelets well-developed; containing empty lemmas, or male; lanceolate; dorsally compressed; 7-8 mm long; longer than fertile; separately deciduous. Companion sterile spikelet glumes chartaceous; villous; acute; muticous, or mucronate, or awned; one glume awned; with 0-2 mm long awn. Companion sterile spikelet lemmas 2; enclosed by glumes. Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; dorsally compressed; 5 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus cuneate; 0.5 mm long; pubescent; base acute; attached obliquely.
Sterile
Basal sterile spikelets well-developed; on lower raceme 2 in number; 0 in upper raceme; lanceolate; 8-9 mm long; larger than fertile. Basal sterile spikelet glumes villous; smooth on margins; lower glume muticous. Companion sterile spikelets well-developed; containing empty lemmas, or male; lanceolate; dorsally compressed; 7-8 mm long; longer than fertile; separately deciduous. Companion sterile spikelet glumes chartaceous; villous; acute; muticous, or mucronate, or awned; one glume awned; with 0-2 mm long awn. Companion sterile spikelet lemmas 2; enclosed by glumes.
Fertile
Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; dorsally compressed; 5 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus cuneate; 0.5 mm long; pubescent; base acute; attached obliquely.
Morphology Reproductive morphology Inflorescences Bracts Glume
Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume lanceolate; 1 length of spikelet; coriaceous; grey, or purple; without keels; keel-less except near apex. Lower glume surface villous. Lower glume apex dentate; 2 -fid. Upper glume linear; coriaceous; without keels.
Morphology Reproductive morphology Flowers Florets
Basal sterile florets barren; without significant palea. Lemma of lower sterile floret lanceolate; 1 length of fertile lemma; hyaline; 2 -veined. Fertile lemma linear; membranous; without keel; 1 -veined. Lemma apex dentate; 2 -fid; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 16-25 mm long overall; with twisted column. Column of lemma awn puberulous, or pubescent; with 0.2-0.4 mm long hairs. Palea absent or minute.
Morphology Reproductive morphology Flowers
Lodicules 2; cuneate; fleshy. Anthers 3. Stigmas 2.
Distribution
Africa: west-central tropical, northeast tropical, east tropical, southern tropical, and south.
Reference
Andropogoneae. WDC.
[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: not 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
  • 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 2024. 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 2024. 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