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  1. Family: Acanthaceae Juss.
    1. Genus: Acanthus L.
      1. Acanthus eminens C.B.Clarke

        This species is accepted, and its native range is Ethiopia to South Sudan and Central Kenya.


    Acanthaceae (part 1), Kaj Vollesen, Flora of Tropical East Africa, 2008

    Shrubby herb or shrub to 3 m tall; young stems glabrous.
    Leaves with petiole 0.5–2(–2.5) cm long; lamina narrowly elliptic to elliptic or obovate in outline, largest 13–37 × 5–15 cm, deeply lobed with large triangular spine-tipped lobes, each lobe with a spine on antrorse side, apex acuminate to cuspidate, spine-tipped, base attenuate to cuneate, glabrous; each node with one to several persistent sharp terete straw-coloured interpetiolar downwardly directed pungent pale yellow spines to 1.5 cm long, occasionally some with a small lamina.
    Cymes solitary or also 2 from upper leaf-pair, (5–)7–30 cm long; rachis upwards pubescent with hairs and few to many short to long capitate glands, with several pairs of sterile bracts at base, sometimes merging into the vegetative leaves; bracts green to purplish, ovate to elliptic, finely puberulous to sparsely pubescent and upwards with few to many stalked capitate glands, 1.4–2.8 cm long in middle of cyme, spine-tipped and with 4–8 teeth per side (rarely entire); bracteoles subulate to linear, 5–11 mm long, entire.
    Calyx green to purplish, puberulous and with few to many stalked capitate glands; dorsal and ventral sepals longer than bract, oblong-obovate, similar or dorsal slightly longer, 2.1–4 cm long, dorsal entire or 2–3-toothed, ventral 2–3-toothed or irregularly toothed, lateral lanceolate, 1.3–2.5 cm long, acuminate.
    Corolla dark blue to dark purple (rarely pale blue to almost white); tube 4–5 mm long below thickened rim which is 3–4 mm long; limb 5-lobed, 3.5–5 × 3.5–5 cm, below puberulous with hairs and capitate glands, above glabrous; callus with narrow central groove.
    Filaments 1.7–2.2 cm long, glabrous or with stalked glands near apex; anthers 6–9 mm long, densely glandular dorsally.
    Capsule 2.3–2.5 cm long.
    Seed ellipsoid to round, 9–10 mm long, glabrous.
    Range: Uganda. Range: Sudan (Imatong Mts), Ethiopia Range: Kenya. Flora districts: U3 K3 K4 K5 K6 Range: Sudan (Imatong Mts), Ethiopia
    Primary and disturbed wet evergeen montane forest, forest margins, secondary grassland, often forming large stands, occasionally used as a hedge plant; (1200–)1500–2600 m
    Always easily recognised by the spinose nodes and large sepals combined with small bracts. This species must surely also occur in the N Ugandan mountains ( U 1) as it is common in the Imatong Mts on the Sudan side.



    Native to:

    Ethiopia, Kenya, Sudan, Uganda

    Other Data

    Acanthus eminens C.B.Clarke appears in other Kew resources:

    Date Reference Identified As Barcode Type Status
    Feb 11, 1897 Scott Elliot, G.F. [6926], Kenya K000394426 holotype


    First published in D.Oliver & auct. suc. (eds.), Fl. Trop. Afr. 5: 107 (1899)

    Accepted by

    • Darbyshire, I., Kordofani, M., Farag, I., Candiga, R. & Pickering, H. (eds.) (2015). The Plants of Sudan and South Sudan: 1-400. Kew publishing, Royal Botanic Gardens, Kew.
    • Fischer, E., Rembold, K., Althof, A. & Obholzer, J. (2010). Annotated checklist of the vascular plants of Kakamega forest, Western province, Kenya Journal of East African Natural History 99: 129-226.
    • Vollesen, K. (2008). Flora of Tropical East Africa, Acanthaceae(1): 1-285.
    • Hedberg, I., Kelbessa, E., Edwards, S., Demissew, S. & Persson, E. (eds.) (2006). Flora of Ethiopia and Eritrea 5: 1-690. The National Herbarium, Addis Ababa University, Ethiopia & The Department of Systematic Botany, Upps.
    • Govaerts, R. (1995). World Checklist of Seed Plants 1(1, 2): 1-483, 529. MIM, Deurne.


    Flora of Tropical East Africa

    • K.B. 62: 239 (2007).
    • F.E.E. 5: 355 (2006)
    • Biol. Skr. 51(2): 435 (2005)
    • Lebrun & Stork, Enum. Pl. Afr. Trop. 4: 466 (1997)
    • K.T.S.L.: 596 (1994)
    • U.K.W.F., ed. 2: 274 (1994)
    • Blundell, Wild Fl. E. Afr.: 385, fig. 601 (1987)
    • E.P.A.: 952 (1964)
    • K.T.S.: 16 (1961)
    • F.P.S. 3: 166 (1956)
    • K.B. 1933: 94 (1934)
    • F.T.A. 5: 107 (1899)


    Flora of Tropical East Africa
    Flora of Tropical East Africa

    Herbarium Catalogue Specimens
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    Kew Backbone Distributions
    The International Plant Names Index and World Checklist of Selected Plant Families 2020. Published on the Internet at and
    © Copyright 2017 World Checklist of Selected Plant Families.

    Kew Names and Taxonomic Backbone
    The International Plant Names Index and World Checklist of Selected Plant Families 2020. Published on the Internet at and
    © Copyright 2017 International Plant Names Index and World Checklist of Selected Plant Families.