Asteraceae
Lactuca

Lactuca imbricata Hiern

First published in Cat. Afr. Pl. 1: 620 (1898)
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 ± robust perennial herb to 1 m. tall, exceptionally to c. 2 m. tall; rootstock semi-woody, narrowly turbinate.
Morphology Stem
Stems solitary, sometimes several, branching above, ± crowded leafy below, green occasionally purple-tinged, ± glaucous, glabrous or sometimes sparsely setulose.
Morphology Leaves
Leaves ascending or ± appressed to the stem, sessile membranous mostly pinnatipartite with a linear rhachis, up to c. 30 cm. long, elliptic in outline, remotely denticulate on the margins, glabrous or the midrib setose beneath; terminal lobe up to c. 12 x 0.7 cm., linear-lanceolate; lateral lobes in c. 5 pairs, remote, up to c. 8 x 0.6 cm., linear-lanceolate; basal leaves sometimes smaller and undivided, linear-lanceolate, remotely dentate, their lower portions often persisting as chartaceous scales, dark-brown lanate in the axils.
Morphology Reproductive morphology Inflorescences Synflorescence
Synflorescences terminal, laxly paniculate or corymbiform; branches up to c. 50 cm. long, divaricate, glabrous.
Morphology Reproductive morphology Inflorescences Capitulum
Capitula stalked; involucres 15–23 x 6–8 mm. at time of flowering, increasing to c. 30 x 10 mm. in fruiting capitula, conical-cylindric becoming campanulate.
Morphology Reproductive morphology Inflorescences Bracts Phyllaries
Phyllaries imbricate increasing uniformly in length towards the inside, the outermost broadly ovate and rounded-obtuse, the innermost narrowly lanceolate and attenuate, ciliolate above otherwise glabrous, guttulate on exposed areas, usually glaucous, purple-tinged above and on the margins.
Morphology Reproductive morphology Flowers Florets
Florets c. 20 per capitulum.
Morphology Reproductive morphology Flowers Corolla
Corollas yellowish-green, 14–23 mm. long, overtopping the involucres; tube narrowly cylindric, pilose at the throat outside, ligule c. 11 x 1.5 mm., lorate.
Morphology Reproductive morphology Fruits
Achenes reddish-brown, c. 12 x 2.5 mm. including the 4–5 mm. long beak, narrowly flattened-ellipsoid, broadly-ribbed on the margins with 1–2 smaller ribs between, hispidulous; pappus several-seriate, of fine white, barbellate setae, c. 11 mm. long.
[FZ]

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

Morphology General Habit
Perennial herb to 1(–2) m high; taproot semi-woody, over 2.5 cm in diameter, root-crown with old leaf-bases, lanate in the axils; stem usually solitary, pale glaucous green, sometimes purplish, bearing both leaves and capitula, glabrous or sparsely setose.
Morphology Leaves
Leaves ascending, pale glaucous green, sometimes with red-purple margin, sessile, membranous, mostly pinnatipartite, 5–35 cm long, base attenuate towards the amplexicaul part, rachis linear or narrowly lanceolate with 2–4 alternate lobes to 5 cm long and 0.3–0.6 cm wide, margins remotely denticulate, apices acute, glabrous or setose on the midrib beneath.
Morphology Reproductive morphology Inflorescences Capitulum
Capitula many, in lax panicles to 50 cm long; involucre conical-cylindric, lengthening to campanulate after flowering, 15–30 mm long; phyllaries glaucous green with reddish tinge, ovate to lanceolate, 2–28 mm long, acute, papillose, with little hair-tufts at the apices.
Morphology Reproductive morphology Flowers Florets
Florets ± 20; corolla pale yellow, tube cylindric, 8–10 mm long, pilose near the mouth, ligules 8–11 mm long, 1.5–2.5 mm wide.
Morphology Reproductive morphology Fruits
Achenes reddish brown, flattened ellipsoid, 8.5–10 mm including the 1.5–2 mm long beak, 1-ribbed on each side, minutely puberulous; pappus white, 9–13 mm long.
Figures
Fig. 20/7 (achene).
Habitat
Brachystegia woodland or roadside grassland; 950–1250 m
Distribution
T2 T8
[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 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

    • 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