1. Family: Polygonaceae Juss.
    1. Oxygonum Burch. ex Campd.

      1. This genus is accepted, and is native to Africa and Asia-Temperate..

    [FZ]

    Flora Zambesiaca. Vol. 9, Part 3. Polygonaceae-Myriaceae. Pope GV, Polhill RM, Martins ES. 2006.

    Habit
    Annual or perennial polygamous herbs, more rarely shrubs, glabrous or hairy, sometimes with papillae or scales A shrub or scrambling plant from a woody rootstock, ± pubescent Annual or perennial polygamous herbs, more rarely shrubs, glabrous or hairy, sometimes with papillae or scales.
    Leaves
    Leaves alternate, sessile or petiolate, entire or pinnatifid Leaves alternate, sessile or petiolate, entire or pinnatifid. Leaves sessile, dull green, 2–6.8 × 0.3–1.3(1.7) cm, elliptic.lanceolate, acute at the apex often mucronate, attenuate to the base, entire or slightly sinuous on the margin, with the midrib prominent beneath, ± pubescent and punctate with black dots on both surfaces
    Ocrea
    Ocrea membranous or chartaceous, with or without a fringe of setae at the apex Ocrea membranous or chartaceous, with or without a fringe of setae at the apex. Ocrea 10–15 mm long, chartaceous, thinly covered with short hairs, truncate and fringed with red-brown setae c. 8 mm long at the apex
    Stem
    Stems sometimes much branched; branches ascending; bark red-brown
    Flowers
    Hermaphrodite flowers heterostylous; perianth wine-red outside and white inside, tubular with 5 spreading lobes; tube 6–8 mm long and slightly constricted at the apex; lobes 5–8 mm long, oblong-lanceolate or oblong-oblanceolate, acute or apiculate at the apex Flowers pedicellate, clustered in axils of bracts, borne in slender or laxly spiciform, terminal or axillary, leafless racemes; bracteoles 2, united; pedicels becoming thicker and sometimes longer as the fruit matures Hermaphrodite flowers heterostylous, 4–5-merous; perianth tubular, with relatively short lobes; as the fruit matures the receptacle enlarges and invests the fruit with the withered perianth persisting above it and constricted at the base; stamens 8 in 2 series, the 5 outer stamens adnate to the perianth segments near their bases, the 3 inner with flattened bases forming a contiguous ring around the base of the style; anthers oblong; styles 3; stigmas capitate Hermaphrodite flowers heterostylous, 4–5-merous; perianth tubular, with relatively short lobes; as the fruit matures the receptacle enlarges and invests the fruit with the withered perianth persisting above it and constricted at the base; stamens 8 in 2 series, the 5 outer stamens adnate to the perianth segments near their bases, the 3 inner with flattened bases forming a contiguous ring around the base of the style; anthers oblong; styles 3; stigmas capitate. Male flowers with a short tube and 4–5 petaloid perianth segments Flowers pedicellate, clustered in axils of bracts, borne in slender or laxly spiciform, terminal or axillary, leafless racemes; bracteoles 2, united; pedicels becoming thicker and sometimes longer as the fruit matures. Male flowers with a short tube and 4–5 petaloid perianth segments. Male flowers not seen Flowers pedicellate, 1–3 in the axils of bracts, arranged in terminal spiciform rigid racemes c. 25 cm long; bracts 7–10 mm long, chartaceous, obliquely truncate and produced dorsally into an acute or acuminate setose apex, glabrous or ± puberulous; bracteoles 2, c. 5 mm long, hyaline with 1–2 short setae at the apex; pedicels c. 6 mm long, articulated near the apex
    Filaments
    Filaments (1.5)4–11 mm long, filiform; anthers 1–1.3 × 0 4–0.5 mm
    Ovary
    Ovary 7–8 mm long, ellipsoid, glabrous; styles of long-styled flowers 6–7 mm long; styles of short-styled flowers 4–5 mm shorter than the stamens
    Fruits
    Nut red-brown at maturity, 9–12 × 4–5 mm, oblong-ellipsoid, glabrous, longitudinally sulcate and transversally wrinkled. Fruiting receptacle hardened and enclosing the fruit Fruiting receptacle hardened and enclosing the fruit. Nut fusiform, conical, ampulliform or lanceolate-ampulliform, trigonous or not, unarmed or with 3(9) spreading prickles or teeth of varying size and development at the centre or below, or at the base, sometimes winged. Nut fusiform, conical, ampulliform or lanceolate-ampulliform, trigonous or not, unarmed or with 3(9) spreading prickles or teeth of varying size and development at the centre or below, or at the base, sometimes winged.
    Ecology
    Miombo and Cryptosepalum woodland, often on Kalahari Sands; 1000–1750 m.
    Distribution
    A genus of c. 35 species, mostly confined to Africa where it is widespread, one species being endemic in Madagascar. ZAM B, ZAM N, ZAM W Zambia Also in Angola and Dem. Rep. Congo.
    [FTEA]

    Polygonaceae, R. A. Graham. Flora of Tropical East Africa. 1958

    Habit
    Polygamous, heterostylous, annual or perennial herbs or more rarely shrubs
    Ocrea
    Ocreae with or without a terminal fringe of setae
    Flowers
    Flowers borne in axillary, leafless, often triquetrous, rather slender and elongated spiciform racemes Hermaphrodite flowers tubular, the tepals marcescent, the tube very accrescent around the ovary Male flowers with a very short tube and 4–5 petaloid tepals
    Bracteoles
    Bracteoles 2, conjoined
    Male
    Male flowers with a very short tube and 4–5 petaloid tepals
    Hermaphrodite
    Hermaphrodite flowers tubular, the tepals marcescent, the tube very accrescent around the ovary
    Stamens
    Stamens 8, in 2 series; 5 outer adnate to the tepals near their bases, 3 inner with flattened bases forming a contiguous ring around the base of the style
    Pistil
    Styles 3, free or conjoined below; stigmas capitate
    Fruits
    Fruiting perianth fusiform, conical, ampulliform or lanceolate-ampulliform, trigonous or not, unarmed, or with 3 (–9) spreading prickles of varying size and development at the centre or below, or at the base, rarely with 3 additional prickles or teeth on the angles of the lower half, sometimes winged.

    Images

    Distribution

    Native to:

    Angola, Botswana, Burundi, Cape Provinces, Caprivi Strip, Chad, Djibouti, Eritrea, Ethiopia, Free State, Kenya, KwaZulu-Natal, Madagascar, Malawi, Mozambique, Namibia, Niger, Northern Provinces, Rwanda, Saudi Arabia, Socotra, Somalia, Sudan, Swaziland, Tanzania, Uganda, Yemen, Zambia, Zaïre, Zimbabwe

    Introduced into:

    India, Mauritius

    Oxygonum Burch. ex Campd. appears in other Kew resources:

    First published in Monogr. Rumex: 18 (1819)

    Accepted by

    • Schuster, T.M., Reveal, J.L., Bayly, M.J. & Kron, K.A. (2015). An updated molecular phylogeny of Polygonoideae (Polygonaceae): relationships of Oxygonum, Pteroxygonum, and Rumex, and a new circumscription of Koenigia Taxon 64: 1188-1208.

    Literature

    Flora Zambesiaca
    • Bothalia 18: 173–181 (1988).
    • Germishuizen in Bothalia 18: 173–181 (1988).
    • F.T.E.A., Polygonaceae: 26–38 (1958).
    • in F.T.E.A., Polygonaceae: 26–38 (1958).
    • Kew Bull. 12: 145–172 (1957)
    • Graham in Kew Bull. 12: 145–172 (1957)
    • Bull. Jard. Bot. État 17: 157–164 (1944).
    • Robyns in Bull. Jard. Bot. État 17: 157–164 (1944).
    • Meisner in de Candolle, Prodr. 14: 38–39 (1856).
    • de Candolle, Prodr. 14: 38–39 (1856).
    • Monogr. Rumex: 14, 18 & 19 (1819).
    • Monogr. Rumex: 14, 18 & 19 (1819).
    Flora of Tropical East Africa
    • R. Grah. in K.B. 1957: 145 (1957)
    • Trav. 1: 548 (1822)

    Sources

    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

    Kew Backbone Distributions
    The International Plant Names Index and World Checklist of Selected Plant Families 2019. 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 2019. 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