Poaceae
Hyparrhenia

Hyparrhenia umbrosa (Hochst.) Andersson ex Clayton

First published in Kew Bull., Addit. Ser. 2: 127 (1969)
This species is accepted
The native range of this species is Nigeria to Cameroon, South Sudan to E. Tropical Africa, Comoros, S. Africa. It is a perennial and grows primarily in the seasonally dry tropical biome.

Descriptions

Gramineae, W. D. Clayton. Flora of West Tropical Africa 3:2. 1972

Morphology General Habit
Culms stout, 1·2–1·8 m. high
Ecology
Highland grassland, by roadsides and in old cultivation.
[FWTA]

Morphology General Habit
Perennial; caespitose. Rhizomes short. Butt sheaths glabrous. Culms decumbent; robust; 130-200 cm long; 3-6 mm diam.; with prop roots. Leaves cauline. Ligule an eciliate membrane; 2 mm long. Leaf-blades 30-60 cm long; 6-12 mm wide. Leaf-blade surface glabrous.
Morphology Reproductive morphology Inflorescences
Synflorescence compound; paniculate; 20-30 cm long; dense. Inflorescence composed of racemes; terminal and axillary; subtended by a spatheole; embraced at base by subtending leaf, or enclosed. Spatheole ovate; 1.2-2.3 cm long; membranous; brown; glabrous, or pilose. Peduncle 0.3-1.3 cm long; pilose above. Racemes 2; paired; deflexed; 1 cm long; bearing few fertile spikelets; bearing 2-3 fertile spikelets on each. Rhachis fragile at the nodes; ciliate on margins. Rhachis hairs white. Rhachis internodes linear. Rhachis internode tip oblique; flat. Raceme-bases flattened; subequal; 0.5 mm long; stiffly setose. 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; 5-6 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; 5-6 mm long; longer than fertile; separately deciduous. Companion sterile spikelet glumes chartaceous; villous; acute; muticous, or mucronate. Companion sterile spikelet lemmas 2; enclosed by glumes. Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; dorsally compressed; 4 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus oblong; 0.4 mm long; pubescent; base obtuse (broadly); attached obliquely.
Sterile
Basal sterile spikelets well-developed; on lower raceme 2 in number; 0 in upper raceme; lanceolate; 5-6 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; 5-6 mm long; longer than fertile; separately deciduous. Companion sterile spikelet glumes chartaceous; villous; acute; muticous, or mucronate. 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; 4 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus oblong; 0.4 mm long; pubescent; base obtuse (broadly); 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; 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; 7-13 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 tropical, west-central tropical, northeast tropical, east tropical, and south.
Reference
Andropogoneae. WDC.
[GB]

Gramineae, W. D. Clayton, S. M. Phillips & S. A. Renvoize. Flora of Tropical East Africa. 1974

Morphology General Habit
Perennial, arising from a slender rhizome; culms 1.3–2 m. high, slender and rambling below, then becoming thicker, up to 6 mm. in diameter, supported by stilt roots and erect.
Morphology Leaves
Leaf-blades up to 60 cm. long, 12 mm. wide.
Morphology Reproductive morphology Inflorescences
False panicle narrowly oblong, dense, 20–30 cm. long; spatheoles narrowly ovate, 1.2–2.3 cm. long, russet-brown, the peduncles 1/4–1/2 as long; racemes 1–1.2 cm. long, 4–6-awned per pair, deflexed; raceme-bases subequal, the upper 0.5 mm. long, flattened, stiffly bearded. Homogamous pairs 1 at the base of the lower raceme only.
Morphology Reproductive morphology Inflorescences Spikelets
Sessile spikelet 3.5–4.5 mm. long, white villous; callus oblong, 0.4 mm. long, rounded; awn 0.7–1.3 cm. long. Pedicelled spikelet white villous, muticous or mucronate.
Sessile
Sessile spikelet 3.5–4.5 mm. long, white villous; callus oblong, 0.4 mm. long, rounded; awn 0.7–1.3 cm. long.
Pedicelled
Pedicelled spikelet white villous, muticous or mucronate.
Habitat
By roadsides and in old cultivation; 1500–2300 m.
Distribution
K4 K6 T4 T7 U1 U2 widely scattered in tropical and South Africa, but not common
[FTEA]

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

  • Flora of Tropical East Africa

    • Flora of Tropical East Africa
    • http://creativecommons.org/licenses/by-nc-sa/3.0

  • Flora of West Tropical Africa

    • Flora of West Tropical Africa
    • http://creativecommons.org/licenses/by-nc-sa/3.0

  • 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