Asteraceae
Lactuca

Lactuca setosa Stebbins ex C.Jeffrey

First published in Kew Bull. 18: 444 (1966)
This species is accepted
The native range of this species is Tanzania to S. Tropical Africa.

Descriptions

Compositae, G. V. Pope. Flora Zambesiaca 6:1. 1992

Morphology General Habit
An erect perennial herb up to 95(120) cm. tall, from a stout fusiform taproot.
Morphology Stem
Stems solitary, simple below branching above, leafy with leaves ± crowded below, often purplish towards the base, sparsely to densely glandular-setose, or glabrescent; setae 0.5–2 mm. long, patent, gland-tipped.
Morphology Leaves
Lower leaves crowded or sub-rosulate, 3.5–16 x 2–6.5 cm., ± broadly elliptic or oblanceolate, acute to obtuse mucronate at the apex, cuneate below with a tapering-winged petiole-like midrib, irregularly denticulate, ciliate between the teeth, glabrous, or densely setose on the midrib, occasionally sparsely puberulent beneath, lateral nerves ± prominent beneath; upper leaves more spaced, decreasing in size towards the stem apex, becoming oblong-lanceolate sessile and semi-amplexicaul.
Morphology Reproductive morphology Inflorescences Synflorescence
Synflorescences corymbose-paniculate with spreading-ascending branches up to c. 25 cm. long, or contracted and ± globose; bracts subtending the lower branches foliaceous up to 3 cm. long and narrowly lanceolate.
Morphology Reproductive morphology Inflorescences Capitulum
Capitula shortly stalked or subsessile, often ± aggregated.
Morphology Reproductive morphology Inflorescences Bracts Involucre
Involucres 5–8 x 1.5–2 mm. at time of flowering, cylindric, increasing to c. 12 x 2.5 mm. in fruiting capitula.
Morphology Reproductive morphology Inflorescences Bracts Phyllaries
Phyllaries 3–4-seriate somewhat rugulose outside and ciliolate above, glabrous or rarely glandular-setulose on the midrib; the outermost c. 3 mm. long, ovate; the innermost up to c. 12 mm. long and lanceolate-lorate, obtuse, margins entire and narrowly hyaline.
Morphology Reproductive morphology Flowers Florets
Florets c. 5 per capitulum.
Morphology Reproductive morphology Flowers Corolla
Corollas yellow, 8–11.5 mm. long; tube narrowly cylindric; ligule 4–7 mm. long, lorate, lobes c. 1 mm. long apically papillose.
Morphology Reproductive morphology Fruits
Achenes not or hardly beaked, reddish-brown, 4.5–5.8 mm. long, narrowly ellipsoid, or obovoid and ± truncate above, somewhat laterally compressed, broadly ribbed on the margins with 2–5 narrower ribs between, hispidulous on ribs; pappus several-seriate, of numerous white barbellate setae c. 5.5 mm. long.
[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: not threatened. Confidence: confident
[AERP]

Compositae, H. Beentje, C. Jeffrey & D.J.N. Hind. Flora of Tropical East Africa. 2005

Morphology General Habit
Perennial herb, scapose; stem(s) annual, 1–3, erect, 0.7–1.5 m high, bearing both leaves and capitula, sparsely to densely glandular-setose; roots tuberous, like a carrot.
Morphology Leaves
Leaves 4–9, of which 1–3 radical, sessile, elliptic or lanceolate, 3.5–16 cm long, 0.7–6.5 cm wide, base attenuate in radical leaves to subamplexicaul in cauline leaves, margins sinuate-dentate, apex acute or obtuse and mucronate, glabrous or beneath sparsely setose on the veins.
Morphology Reproductive morphology Inflorescences Capitulum
Capitula many, in lax panicles; stalks of individual capitula absent or up to 2 cm long; involucre cylindric, 7–12 mm long; phyllaries 3-seriate, lanceolate, 2.5–12 mm long, glabrous or nearly so, the very apex minutely puberulous.
Morphology Reproductive morphology Flowers Florets
Florets ± 5 per capitulum; corolla yellow, tube cylindric, 4–4.5 mm long, ligule 7–9 mm long, 2–2.5 mm wide.
Morphology Reproductive morphology Fruits
Achenes fusiform, 4.5–6 mm long, 3-ribbed on each side, minutely pilose, hardly beaked; pappus white, 4–6.5 mm long.
Figures
Fig. 20/3 (achene).
Habitat
Marshy grassland; 1400–1800 m
Distribution
T4 T7
[FTEA]

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

  • Flora of Tropical East Africa

    • Flora of Tropical East Africa
    • 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