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  1. Family: Acanthaceae Juss.
    1. Genus: Acanthus L.
      1. Acanthus polystachyus Delile

        This species is accepted, and its native range is Ethiopia to NW. Tanzania.

    [FTEA]

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

    Habit
    Shrub to 4 m tall; young stems puberulous to tomentellous (rarely glabrous).
    Leaves
    Leaves with petiole 0.3–2.2(–2.5) cm long; lamina ovate to elliptic in outline, largest 11–35 × 6–16 cm, deeply lobed with large triangular spine-tipped lobes, each lobe with 1–2 spines on antrorse side or on both sides, apex acute to acuminate, spine-tipped, base truncate to cordate, beneath sparsely puberulous to tomentellous (rarely glabrous) on midrib and larger veins, glabrous to puberulous on lamina, above sparsely to densely pubescent on midrib and glabrous or with scattered long hairs on lamina (rarely uniformly puberulous); stipule-like interpetiolar leaves present, but often falling quickly, with lamina, up to 1.5 cm long, spiny.
    Inflorescences
    Cymes solitary or also 2–4 from upper axils, 4–25(–30) cm long; rachis puberulous to tomentose, with several pairs of sterile bracts at base; bracts pale green to straw-coloured, elliptic to slightly obovate, puberulous to densely pubescent (rarely almost glabrous but for ciliate margin), 1.4–2.8 cm long in middle of cyme, spine-tipped and with (5–)10–25 large and small teeth per side, longest 3–5 mm long, small teeth inserted between large, teeth hairy near base; bracteoles linear-lanceolate, 1–2.5 cm long, toothed in apical part.
    Calyx
    Calyx green or tinged purplish, glabrous to densely puberulous or pubescent, conspicuously ciliate; dorsal and ventral sepals ovate or broadly so, dorsal 1.4–2.2 cm long, obtuse or with 1–3-toothed tip and without or with 1(–4) weak lateral teeth per side, ventral 1.1–1.8 cm long, obtuse or with spiny tip or with 2 small additional apical teeth or with 2 triangular spine-tipped lobes, lateral ovate, 0.8–1.4 cm long, obtuse or acuminate.
    Corolla
    Corolla pale pink to pink or rose (more rarely white); tube 3–5 mm long below thickened rim which is 3–5 mm long; limb 5-lobed, 2.5–4 × 3–4 cm, below densely puberulous, above puberulous (rarely glabrous); callus with broad central groove and two narrow lateral ridges.
    Filaments
    Filaments 1.4–2.4 cm long, glabrous or 2 dorsal hairy on inside near base; anthers 3.5–5 mm long, glabrous or with long curly hairs on sides and back.
    Fruits
    Capsule 1.7–2.4 cm long.
    Seeds
    Seed ellipsoid to round, 7–9 mm long, glabrous.
    Figures
    Fig. 15.
    Distribution
    Range: Kenya. Range: Uganda. Range: Sudan, Ethiopia, Congo-Kinshasa, Rwanda, Burundi Range: Tanzania. Range: Sudan, Ethiopia, Congo-Kinshasa, Rwanda, Burundi Flora districts: U2 U 3, U 4; K3 K5 T1 T4
    Ecology
    Tall fireswept seasonally wet grassland, often forming dense stands at forest margins, rocky hills; 1100–2300 m
    Note
    Ups. 29, 3: 160 (1991) reports A. pubescens from both E and W Usambara Mts. It often forms a 5–10 m wide belt between the forest and the tall grassland, thus protecting the forest from the grassfires and eventually allowing the forest to expand. Iversen in Symb. Occasionally these are cultivated in Kenya. No species of Acanthus has been collected in the Usambaras; it is unclear what Iversens records refer to. White-flowered forms are apparently much more common in Uganda than elsewhere. One of the most characteristic forest margin species in Uganda and NW Tanzania.

    Images

    Distribution

    Native to:

    Burundi, Ethiopia, Kenya, Rwanda, Sudan, Tanzania, Uganda, Zaïre

    Synonyms

    Other Data

    Acanthus polystachyus Delile appears in other Kew resources:

    Date Reference Identified As Barcode Type Status
    Codrington, Ethiopia 25935.000
    Jan 1, 2000 Dawe [237], Uganda Acanthus pubescens K000394423 syntype
    Jan 1, 2000 James, E. [s.n.], Uganda Acanthus pubescens K000394425 syntype
    Jan 1, 2000 Speke [136], Tanzania Acanthus pubescens K000394422 holotype
    Jan 1, 2000 Elliott, C.F. [s.n.], Uganda Acanthus pubescens K000394424 syntype

    Bibliography

    First published in F.Caillaud, Voy. Méroé 1: 2 (1826)

    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.

    Literature

    Flora of Tropical East Africa

    • K.B. 62: 241 (2007).
    • F.E.E. 5: 357 (2006)
    • Lebrun & Stork, Énum. Pl. Afr. Trop. 4: 466 (1997)
    • Senck. Biol. 46: 117 (1965)
    • E.P.A.: 953 (1964)
    • Pichi Sermolli, Miss. Lago Tana 7,1: 140 (1951)
    • Cent. Pl. Méroé: 72, t. 62, f. 2 (1826)

    Sources

    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 Selected Plant Families 2020. Published on the Internet at http://www.ipni.org and http://apps.kew.org/wcsp/
    © Copyright 2017 World Checklist of Selected Plant Families. http://creativecommons.org/licenses/by/3.0

    Kew Names and Taxonomic Backbone
    The International Plant Names Index and World Checklist of Selected Plant Families 2020. Published on the Internet at http://www.ipni.org and http://apps.kew.org/wcsp/
    © Copyright 2017 International Plant Names Index and World Checklist of Selected Plant Families. http://creativecommons.org/licenses/by/3.0