1. Family: Achariaceae Harms
    1. Genus: Caloncoba Gilg
      1. Caloncoba welwitschii (Oliv.) Gilg

        One of the first scientific collections of Caloncoba welwitschii was made by the Austrian collector Friedrich Welwitsch, in Angola in 1855. The specific epithet welwitschii was given to this species in his honour. A pressed and dried specimen of C. welwitschii, collected by Welwitsch, is held in Kew’s Herbarium.


    Flacourtiaceae, Hutchinson and Dalziel. Flora of West Tropical Africa 1:1. 1954

    Forest shrub or tree, to 30 ft. high
    Flowers white.

    Flacourtiaceae, H. Wild. Flora Zambesiaca 1:1. 1960

    Small or medium sized tree up to c. 14 m. tall, branches glabrous or puberulous.
    Leaves collected towards the ends of the branches; lamina up to 25 x 18 cm., membranous, ovate, apex acuminate, base rounded or slightly cordate, 5-nerved from the base; petiole up to 15 cm. long; stipules up to 2.5 cm. long, subulate-aristate, caducous.
    Flowers up to 10 cm. in diam., scented, borne on the previous year’s branches or on older wood, appearing with the young leaves, in fascicles of 2–5; pedicels up to c. 2–5 cm. long, sparingly glandular.
    Sepals 2 x 1.3 cm., imbricate, very concave, glandular on exposed parts outside, oblong.
    Petals white, c. 10, about twice the size of the sepals, spathulate-oblong, tapering to a short basal claw, strongly veined towards the base.
    Stamens very numerous with slender filaments up to 2 cm. long; anthers linear, 4 mm. long, dehiscing by apical slits.
    Ovary tuberculate; placentas 5–6; style slender, c. 1 cm. long, stigma-lobes 5–6, linear, obtuse or capitate.
    Fruit a densely echinate capsule c. 8 cm. in diam. (including spines), with slender spines 1.5–2 cm. long, splitting into 5–6 recurved valves when ripe; style persistent.
    Seeds numerous, 6–7 mm. in diam., globose, puberulous.

    Flacourtiaceae, H. Sleumer (Rijksherbarium, Leiden). Flora of Tropical East Africa. 1975

    Shrub or generally tree, 4–14(–20) m. tall; bark greyish-brownish.
    Leaves ± deciduous, aggregated towards the ends of the branches; blade ovate, apex acuminate, base broadly cuneate to cordate, membranous to chartaceous, glabrous, 10–28 cm. long, (5.5–)8–20 cm. broad, 5-nerved from the base, upper lateral nerves 2–4 pairs, veins ± transverse, prominent beneath with ± pronounced reticulation of the veinlets; petiole 4–12(–19) cm. long; stipules subulate-aristate, up to 2.5 cm. long, caducous.
    Flowers 2–5 in a fascicle from defoliate axils, or from old branches, even from the trunk, appearing with the young leaves, up to 10 cm. in diameter; pedicels sparingly glandular, 1.5–2.5 cm. long at anthesis, up to 4 cm. in fruit.
    Sepals oblong-elliptic, glandular dorsally, subpersistent, 1.2–2 cm. long, 0.7–1.3 cm. broad.
    Petals ± 10, about twice the size of the sepals, spathulate-oblong, strongly veined towards the base, (1.6–)2.5–4.5 cm. long, (0.6–)1–2.3 cm. broad.
    Filaments up to 2.5 cm. long; anthers 3–4 mm. long.
    Ovary tuberculate; style slender, ± 1 cm. long, with 5–6 short stigmatic branches.
    Capsule elliptic to subglobular, 7–10(–15) cm. long, 4–6(–12) cm. across including the spines (these (1.5–)2–5 cm. long), splitting into 5–6 valves, which recurve when ripe; pericarp ± 5 mm. thick.
    Seeds numerous, globose, puberulous, 5–7 mm. long, 3–4 mm. broad.
    Fig. 8/8, 9.

    Kew Species Profiles

    General Description
    In the dense, green, tropical forest undergrowth in Africa, the profusion of petals of the bright white flowers of Caloncoba welwitschii provide quite a spectacle.

    One of the first scientific collections of Caloncoba welwitschii was made by the Austrian collector Friedrich Welwitsch, in Angola in 1855. The specific epithet welwitschii was given to this species in his honour. A pressed and dried specimen of C. welwitschii, collected by Welwitsch, is held in Kew’s Herbarium.

    Species Profile
    Geography and distribution

    Caloncoba welwitschii occurs in Nigeria, Cameroon, Gabon, Democratic Republic of Congo, Congo (Congo Brazzaville), Tanzania, Malawi, and Mozambique.

    Kew expeditions to Mozambique

    Kew botanists, including Tim Harris and Jonathan Timberlake, have recently been on expeditions to Mozambique, during which specimens of Caloncoba welwitschii were collected.


    Overview:  A tree up to 14 m tall, with large leaves (about 25 cm long and 18 cm wide), having a petiole (leaf stalk) up to 15 cm long.

    Leaves:  The stipules (leaf-like structures) found either side of the petiole base are up to 2.5cm long and sometimes fall off soon after the leaf is fully formed.

    Flowers:  The showy, scented flowers are borne on older wood and are up to 10 cm in diameter. Each flower has about 10 white, papery petals and many stamens (male parts). The stamens are held in a cluster around the centre of the flower, and are up to 2 cm long. The style (female part) is about 1 cm long.

    Fruits:  The fruit is about 8 cm across, covered in slender spines, and splits into 5 or 6 sections when mature.

    Seeds:  The numerous, spherical seeds are about 6 mm in diameter.

    Kew's research on this species

    Kew scientists Sue Zmarzty and Mark Chase, are working on C. welwitschii and a group of plants closely related to it, in partnership with botanists at the National Herbarium of the Netherlands (Wageningen).

    They are investigating evidence, some of it from molecular studies (comparing the DNA of various species), that although C. welwitschii belongs to the family Achariaceae, some plants that look very similar may actually belong to a different plant family: the Salicaceae. The Salicaceae includes the willows (such as golden weeping willow) and poplars, as well as many tropical and subtropical plants.


    Caloncoba welwitschii has a wide range of traditional medicinal uses in Central Africa. For example, the leaves and bark are used for treating rheumatism, and are made into poultices for applying to abscesses. The leaf-sap is used to treat headaches, and the plant itself is prescribed as a means of killing body-lice. The fruit pulp is eaten in Gabon. It has been reported that the seed oil is used to treat leprosy in the Democratic Republic of Congo.


    Caloncoba welwitschii is sometimes cultivated as a medicinal plant in tropical Africa.

    This species at Kew

    Both dried and alcohol-preserved specimens of Caloncoba welwitschii are held in Kew’s Herbarium and made available to bona fide researchers by appointment. The details of some of these specimens, including images, can be seen online in Kew’s Herbarium Catalogue.

    The Economic Botany Collection at Kew includes specimens of Caloncoba welwitschii wood that can be examined by researchers by appointment.

    Cameroon, Congo-Brazzaville, Gabon, Malawi, Mozambique, Tanzania
    Understorey of tropical forest; also a component of secondary forest.
    Least Concern according to IUCN Red List criteria.

    The seeds are poisonous when dried and powdered.

    Medicinal, fruit pulp edible.



    Found In:

    Angola, Cabinda, Cameroon, Central African Repu, Congo, Equatorial Guinea, Gabon, Malawi, Mozambique, Nigeria, Tanzania, Zaïre

    Introduced Into:

    Gulf of Guinea Is.

    Caloncoba welwitschii (Oliv.) Gilg appears in other Kew resources:

    Date Identified Reference Herbarium Specimen Type Status
    Jan 1, 1973 unknown K000231149
    Jan 1, 1973 Welwitsch [537], Angola K000231150 isotype
    Jan 1, 1973 Carlos, D., Tanzania K000231152 Unknown type material
    Timberlake, J. [s.n.], Mozambique K000614495
    Harris, T. [583], Mozambique K000614174
    Harris, T. [655], Mozambique K000614235
    Milne-Redhead, E. [7602A], Tanzania 15413.000

    First published in Bot. Jahrb. Syst. 40: 462 (1908)

    Accepted in:

    • [3] Sita, P. & Moutsambote, J.-M. (2005) Catalogue des plantes vasculaires du Congo , ed. sept. 2005: 1-158. ORSTOM, Centre de Brazzaville
    • [4] Govaerts, R. (1999) World Checklist of Seed Plants 3(1, 2a & 2b): 1-1532. MIM, Deurne
    • [6] (1975) Flora of Tropical East Africa , Flacourtiaceae: 1-68
    • [8] (1973) Bulletin of the British Museum (Natural History). Botany 4: 325-411
    • [9] (1968) Flore du Congo du Rwanda et du Burundi , Flacourtiaceae (1): 1-61. Jardin Botanique National de Belgique, Bruxelles
    • [10] (1960) Flora Zambesiaca 1(1): 1-336. Royal Botanic Gardens, Kew
    • [12] (1954-1958) Flora of West Tropical Africa , ed. 2, 1: 1-828


    • [1] The Plant List (2010). Caloncoba welwitschii.
    • [2] (2006) Scripta Botanica Belgica 35: 1-438
    • [5] Burkill, H.M. (1994). The Useful Plants of West Tropical Africa, Volume 2. Royal Botanic Gardens, Kew.
    • [7] Sleumer in A. Engler, Botanische Jahrbücher für Systematik, Pflanzengeschichte und Pflanzengeographie 94: 124 (1974).
    • [11] Wild, H. (1960). Flacourtiaceae. In: Flora Zambesiaca, Volume 1, Part 1, ed. A.W. Exell & H. Wild. A.A. Balkema, Leiden.

    • [13] J.P.M. Brenan, Check-lists of the Forest Trees and Shrubs of the British Empire no. 5, part II, Tanganyika Territory p. 230 (1949).
    • [14] A. Engler & O. Drude, Die Vegetation Der Erde, IX, Pflanzenwelt Afrikas 3 (2): 568 (1921).
    • [15] Gilg in A. Engler, Botanische Jahrbücher für Systematik, Pflanzengeschichte und Pflanzengeographie 40: 462 (1908).
    • [16] in Engl. Bot. Jahrb. 40: 462 (1908).


    Flora of Tropical East Africa
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