1. Family: Polygonaceae Juss.
    1. Genus: Oxygonum Burch. ex Campd.
      1. Oxygonum pachybasis Milne-Redh.

        This species is accepted, and its native range is SW. Tanzania to Angola.

    [FZ]

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

    Type
    Type:Zambia, Solwezi, 20.ix.1930, Milne-Redhead 1162 (K, holotype).
    Habit
    An erect or ± decumbent perennial herb with many stems from a thick woody rootstock An erect or ± decumbent perennial herb with many stems from a thick woody rootstock.
    Stem
    Stems annual, reddish-brown, 8–35 cm long, longitudinally striate, leafless at the base, ± pubescent Stems annual, reddish-brown, 8–35 cm long, longitudinally striate, leafless at the base, ± pubescent.
    Flowers
    Hermaphrodite flowers heterostylous; perianth white with lobes tinged pink outside; tube 1.5–2 mm long, puberulous outside; lobes 4–7 × 3 mm long, ovate-elliptic to oblong-elliptic. Filaments 2–5 mm long; anthers 0.9–1 × 0.35–0.4 mm Flowers pedicellate, 2–6 in the axils of bracts, arranged in terminal and lateral spiciform racemes up to 17 cm long, pedicels 5–8 mm long, accrescent up to 12 mm and reflexed in fruit; bracts chartaceous, obliquely truncate and produced dorsally into an acute subulate seta, sometimes with a fringe of short setae. Male flowers not seen Flowers pedicellate, 2–6 in the axils of bracts, arranged in terminal and lateral spiciform racemes up to 17 cm long, pedicels 5–8 mm long, accrescent up to 12 mm and reflexed in fruit; bracts chartaceous, obliquely truncate and produced dorsally into an acute subulate seta, sometimes with a fringe of short setae Hermaphrodite flowers heterostylous; perianth white with lobes tinged pink outside; tube 1.5–2 mm long, puberulous outside; lobes 4–7 × 3 mm long, ovate-elliptic to oblong-elliptic. Male flowers not seen.
    Ovary
    Ovary 0.5–1 mm long; style connate in the lower c. 2 mm, 3-branched; style of long-styled flowers 4–6.5 mm long; style of short-styled flowers (1)1.5–2.5(3) mm
    Fruits
    Nut reddish-brown when mature, 7–9 × 4–5 mm, ovoid-trigonous, longitudinally striate, unwrinkled or very irregularly wrinkled, puberulous. Nut reddish-brown when mature, 7–9 × 4–5 mm, ovoid-trigonous, longitudinally striate, unwrinkled or very irregularly wrinkled, puberulous.
    Ecology
    Miombo and Cryptosepalum woodland, roadsides, recently burnt ground; 1350–1600 m.
    Note
    Following the study of material from the Flora Zambesiaca area and other countries, we conclude that O. vanderystii Robyns is conspecific with O. pachybasis. Putative differences related to stem length and consistency (Robyns 1944, 1948) and morphology of fruits (Graham 1957) are, in our opinion, questionable: stem length and texture are highly variable and fruits are always trigonous, including those of the type of O. pachybasis.
    Distribution
    ZAM N, ZAM W Also in SW Tanzania, Dem. Rep. Congo and Angola. Zambia
    Leaves
    Leaves 3.5–6 × 0.9–1.3 cm, elliptic-lanceolate to lanceolate, acute apiculate at the apex, attenuate at the base, entire on the margins, pubescent to glabrescent, midrib prominent beneath. Leaves 3.5–6 × 0.9–1.3 cm, elliptic.lanceolate to lanceolate, acute apiculate at the apex, attenuate at the base, entire on the margins, pubescent to glabrescent, midrib prominent beneath
    Ocrea
    Ocrea reddish-brown, 0.8–1.3 cm long, truncate with a fringe of brownish setae 3–7 mm long at the apex, ± pubescent. Ocrea reddish-brown, 0.8–1.3 cm long, truncate with a fringe of brownish setae 3–7 mm long at the apex, ± pubescent
    Male
    Male flowers not seen.
    Stamens
    Filaments 2–5 mm long; anthers 0.9–1 × 0.35–0.4 mm.
    Hermaphrodite
    Filaments 2–5 mm long; anthers 0.9–1 × 0.35–0.4 mm. Ovary 0.5–1 mm long; style connate in the lower c. 2 mm, 3-branched; style of long-styled flowers 4–6.5 mm long; style of short-styled flowers (1)1.5–2.5(3) mm. Hermaphrodite flowers heterostylous; perianth white with lobes tinged pink outside; tube 1.5–2 mm long, puberulous outside; lobes 4–7 × 3 mm long, ovate-elliptic to oblong-elliptic.
    Pistil
    Ovary 0.5–1 mm long; style connate in the lower c. 2 mm, 3-branched; style of long-styled flowers 4–6.5 mm long; style of short-styled flowers (1)1.5–2.5(3) mm.

    Images

    Distribution

    Native to:

    Angola, Tanzania, Zambia, Zaïre

    Oxygonum pachybasis Milne-Redh. appears in other Kew resources:

    Date Reference Identified As Barcode Type Status
    Milne - Redhead, E. [1162], Zambia K000244019 holotype

    First published in Hooker's Icon. Pl. 33: t. 3215 (1933)

    Accepted by

    • Figueiredo, E. & Smith, G.F. (2008). Plants of Angola Strelitzia 22: 1-279. National Botanical Institute, Pretoria.
    • Pope, G.V., Polhill, R.M. & Martins, E.S. (eds.) (2006). Flora Zambesiaca 9(3): 1-277. Royal Botanic Gardens, Kew.
    • Robyns, W. & al. (eds.) (1948-1963). Flore du Congo Belge et du Ruanda-Urundi 1-10.

    Literature

    Flora Zambesiaca
    • Kew Bull. 12: 169 (1957).
    • F.C.B. 1: 405 (1948).
    • Bull. Jard. Bot. État 17: 163 (1944)
    • Hooker’s Icon. Pl. 33: t. 3215 (1933).
    Kew Backbone Distributions
    • Figueiredo, E. & Smith, G.F. (2008). Plants of Angola Strelitzia 22: 1-279. National Botanical Institute, Pretoria.
    • Pope, G.V., Polhill, R.M. & Martins, E.S. (eds.) (2006). Flora Zambesiaca 9(3): 1-277. Royal Botanic Gardens, Kew.
    • Robyns, W. & al. (eds.) (1948-1963). Flore du Congo Belge et du Ruanda-Urundi 1-10.

    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.
    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