1. Family: Polygonaceae Juss.
    1. Genus: Oxygonum Burch. ex Campd.
      1. Oxygonum annuum S.Ortiz & Paiva

        This species is accepted, and its native range is Zambia.

    [FZ]

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

    Habit
    An erect annual herb An erect annual herb.
    Stem
    Stems branching at the base and laxly above, angular-striate, greenish, reddish at the base, with simple white hairs at the base and to a varying extent above Stems branching at the base and laxly above, angular-striate, greenish, reddish at the base, with simple white hairs at the base and to a varying extent above.
    Leaves
    Leaves greenish, (8)20–30(60) × 0.3–0.7(1) mm, narrowly linear, glabrous or with simple white hairs Leaves greenish, (8)20–30(60) × 0.3–0.7(1) mm, narrowly linear, glabrous or with simple white hairs.
    Ocrea
    Ocrea (4)5–6(9) mm long, often 3–4 dentate at the apex, surface glabrous or somewhat pubescent, apex glabrous or with a fringe of c. 0.2 mm long hairs Ocrea (4)5–6(9) mm long, often 3–4 dentate at the apex, surface glabrous or somewhat pubescent, apex glabrous or with a fringe of c. 0.2 mm long hairs.
    Flowers
    Hermaphrodite flowers homostylous or not conspicuously heterostylous; perianth 5-lobed; tube 0.5–1 mm long, pubescent; lobes 1–2(2.5) mm long, white, tinged with pink at the abaxial surface, sometimes pubescent Male flowers not seen Flowers pedicellate, 3(4) in the axils of bracts, 1(2) flowering at a time, arranged in terminal spiciform, slender racemes up to 21 cm long; bracts up to 5 mm long, truncate, sometimes with a acuminate apex up to 1 mm long, glabrous to pubescent, with short apical cilia; pedicels erect, up to 5 mm long, filiform Flowers pedicellate, 3(4) in the axils of bracts, 1(2) flowering at a time, arranged in terminal spiciform, slender racemes up to 21 cm long; bracts up to 5 mm long, truncate, sometimes with a acuminate apex up to 1 mm long, glabrous to pubescent, with short apical cilia; pedicels erect, up to 5 mm long, filiform. Hermaphrodite flowers homostylous or not conspicuously heterostylous; perianth 5-lobed; tube 0.5–1 mm long, pubescent; lobes 1–2(2.5) mm long, white, tinged with pink at the abaxial surface, sometimes pubescent. Male flowers not seen.
    Filaments
    Filaments 0.5–1.5 mm long; anthers 0.5–0.7 mm long
    Ovary
    Ovary c. 1 mm long; styles c. 1.5 mm long
    Ecology
    Sandy roadsides, Guibourtia and Baikiaea woodland, Kalahari Sand; c. 1000–1100 m.
    Note
    The most similar species to O. annuum is O. lineare De Wild., from Dem. Rep. Congo and Angola, which likewise has linear leaves and ellipsoid fruits; however this species can be easily differentiated from O. annuum since it often has stems glabrous at the base, wider leaves ((0.5)1–2.3(9) mm) that are linear to elliptic, more flowers per bract ((4)6–14), the entire corolla always glabrous, longer corolla lobes (2.5–3(3.5) mm), wider fruits (2.5–3(3.5) mm), markedly heterostylous flowers and fruits without transverse wrinkles.
    Distribution
    ZAM B, ZAM W Zambia Also in Angola.
    Male
    Male flowers not seen.
    Stamens
    Filaments 0.5–1.5 mm long; anthers 0.5–0.7 mm long.
    Pistil
    Ovary c. 1 mm long; styles c. 1.5 mm long.
    Hermaphrodite
    Ovary c. 1 mm long; styles c. 1.5 mm long. Filaments 0.5–1.5 mm long; anthers 0.5–0.7 mm long. Hermaphrodite flowers homostylous or not conspicuously heterostylous; perianth 5-lobed; tube 0.5–1 mm long, pubescent; lobes 1–2(2.5) mm long, white, tinged with pink at the abaxial surface, sometimes pubescent.
    Fruits
    Nut 4–5 × 2.3–2.5 mm, ellipsoid, with c. 12 longitudinal ridges and numerous transverse wrinkles, glabrous or pubescent. Nut 4–5 × 2.3–2.5 mm, ellipsoid, with c. 12 longitudinal ridges and numerous transverse wrinkles, glabrous or pubescent.

    Distribution

    Oxygonum annuum S.Ortiz & Paiva appears in other Kew resources:

    Date Reference Identified As Barcode Type Status
    Jan 1, 1998 Robinson, E. A. [6792], Zambia K000244020 holotype

    First published in Bot. J. Linn. Soc. 131: 172 (1999)

    Accepted by

    • Figueiredo, E. & Smith, G.F. (2008). Plants of Angola Strelitzia 22: 1-279. National Botanical Institute, Pretoria.

    Literature

    Flora Zambesiaca
    • Bot. J. Linn. Soc. 131: 172 (1999).
    Kew Backbone Distributions
    • Figueiredo, E. & Smith, G.F. (2008). Plants of Angola Strelitzia 22: 1-279. National Botanical Institute, Pretoria.

    Sources

    Flora Zambesiaca
    Flora Zambesiaca
    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.

    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