Poaceae
Digitaria

Digitaria bidactyla Van der Veken

First published in Bull. Jard. Bot. Natl. Belg. 45: 413 (1975)
This species is accepted
The native range of this species is Zambia. It is an annual and grows primarily in the seasonally dry tropical biome.

Descriptions

Morphology General Habit
Annual; culms solitary, or caespitose. Culms erect; slender; 10-20 cm long. Culm-nodes brown; glabrous. Leaf-sheaths glabrous on surface. Ligule a ciliolate membrane; 1 mm long. Leaf-blades 3-5 cm long; 2-4 mm wide. Leaf-blade surface glabrous. Leaf-blade margins smooth.
Morphology Reproductive morphology Inflorescences
Inflorescence composed of racemes. Racemes 1-2; single, or paired; unilateral; 2-4 cm long. Rhachis broadly winged; with sharp-edged midrib; 0.3-0.5 mm wide; scabrous on margins. Raceme-bases filiform. Spikelets solitary. Fertile spikelets pedicelled. Pedicels angular; 0.5-1 mm long; smooth; puberulous; hairy at tip; tip widened.
Morphology Reproductive morphology Inflorescences Spikelets
Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; dorsally compressed; gibbous; 2.3-2.5 mm long; with hairs extending 1 mm beyond apex; falling entire.
Fertile
Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; dorsally compressed; gibbous; 2.3-2.5 mm long; with hairs extending 1 mm beyond apex; falling entire.
Morphology Reproductive morphology Inflorescences Bracts Glume
Glumes one the lower absent or obscure; shorter than spikelet; thinner than fertile lemma. Upper glume oblong; gibbous; 0.66 length of spikelet; membranous; without keels; 3 -veined. Upper glume surface pilose. Upper glume apex acute.
Morphology Reproductive morphology Flowers Florets
Basal sterile florets barren; without significant palea. Lemma of lower sterile floret lanceolate; 1 length of spikelet; membranous; 5 -veined; pilose; acute. Fertile lemma lanceolate; gibbous; 2-2.3 mm long; cartilaginous; much thinner on margins; yellow; keeled. Lemma margins flat; covering most of palea. Lemma apex acuminate. Palea cartilaginous.
Distribution
Africa: southern tropical.
Reference
Paniceae. FZ.
[GB]

Gramineae, W. D. Clayton. Flora Zambesiaca 10:3. 1989

Morphology General Habit
A loosely caespitose or solitary growing, slender annual.
Morphology Culms
Culms 10–20 cm., erect, glabrous, nodes dark and glabrous.
Morphology Leaves Leaf sheaths
Leaf sheaths glabrous.
Morphology Leaves Ligules
Ligule c. 1 mm. long, rim-like, ciliate.
Morphology Leaves Leaf lamina
Leaf laminae 3–5 × 0.2–0.4 cm., linear, flat, glabrous on both surfaces, with smooth margins.
Morphology Reproductive morphology Inflorescences
Inflorescence composed of 1–2 racemes, 2–4 cm. long, often patent, both shortly peduncled.
Morphology Leaves Rachis
Rhachis triquetrous, asymmetrically winged, undulating, up to 0.5 mm. wide, smooth with smooth and not thickened margins.
Morphology Reproductive morphology Flowers Pedicel
Pedicels solitary (sometimes a reduced subsessile spikelet present), 0.5–1 mm. long, triangular, smooth, broadened at the apex, which bears a coronula.
Morphology Reproductive morphology Inflorescences Spikelets
Spikelets 2.3–2.5 mm. long, lanceolate, basally adaxially gibbous.
Morphology Reproductive morphology Inflorescences Bracts Glume
Inferior glume absent. Superior glume c.2/3 of the spikelet, oblong-triangular, 3-nerved, appressed hairy, hairs white, stiff, acute, overtopping the superior glume.
Inferior
Inferior glume absent. Inferior lemma as long as the spikelet, lanceolate with recurved margins, 5-nerved, appressed hairy, hairs overtopping the spikelet for c. 1 mm.
Morphology Reproductive morphology Inflorescences Bracts Lemma
Superior lemma conspicuously shorter than the spikelet, lanceolate, slightly acuminate, basally gibbous, somewhat keeled, pale yellow or sometimes purplish tinged. Inferior lemma as long as the spikelet, lanceolate with recurved margins, 5-nerved, appressed hairy, hairs overtopping the spikelet for c. 1 mm.
Superior
Superior lemma conspicuously shorter than the spikelet, lanceolate, slightly acuminate, basally gibbous, somewhat keeled, pale yellow or sometimes purplish tinged. Superior glume c.2/3 of the spikelet, oblong-triangular, 3-nerved, appressed hairy, hairs white, stiff, acute, overtopping the superior glume.
[FZ]

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

  • Flora Zambesiaca

    • Flora Zambesiaca
    • 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 2025. 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 2025. 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