1. Family: Polygonaceae Juss.
    1. Genus: Oxygonum Burch. ex Campd.
      1. Oxygonum buchananii (Dammer) J.B.Gillett

        This species is accepted, and its native range is SW. Tanzania to S. Tropical Africa.

    [FZ]

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

    Type
    Lectotype, selected by Graham (1957): Malawi, Buchanan 550 (K, lectotype).
    Habit
    A robust perennial herb, sometimes bushy, with a rootstock A robust perennial herb, sometimes bushy, with a rootstock.
    Stem
    Stems several from the rootstock, up to 1 m long, prostrate or spreading, longitudinally striate, glabrous or sparsely papillate Stems several from the rootstock, up to 1 m long, prostrate or spreading, longitudinally striate, glabrous or sparsely papillate.
    Leaves
    Leaves petiolate, dark green above, paler beneath; lamina 7.5–10 × 4.5–6 cm, obovate to broadly ovate, obtuse or shortly acuminate at the apex, attenuate at the base and decurrent on the petiole, with the midrib prominent beneath, entire or slightly wavy on the margin, glabrous on both surfaces, gland-dotted beneath; petiole 1–2 cm long Leaves petiolate, dark green above, paler beneath; lamina 7.5–10 × 4.5–6 cm, obovate to broadly ovate, obtuse or shortly acuminate at the apex, attenuate at the base and decurrent on the petiole, with the midrib prominent beneath, entire or slightly wavy on the margin, glabrous on both surfaces, gland-dotted beneath; petiole 1–2 cm long.
    Ocrea
    Ocrea brown, 0.5–2 cm long, glabrous outside, truncate with a terminal fringe of 7–9 setae 1–3 cm long Ocrea brown, 0.5–2 cm long, glabrous outside, truncate with a terminal fringe of 7–9 setae 1–3 cm long.
    Flowers
    Male flowers not seen Flowers pedicellate, 2–4 in the axils of bracts, arranged in elongated spiciform terminal racemes up to 36 cm long; bracts 4–5 mm long, truncate but produced dorsally into an acute setose apex, with or without a terminal fringe of short setae up to 1 mm long; pedicels red-brown, 6–7 mm long, glabrous Hermaphrodite flowers heterostylous, long-styled flowers not seen; perianth yellowish-green, glabrous, 5-lobed; tube 2–3 mm long; lobes 3–4 mm long, oblong Flowers pedicellate, 2–4 in the axils of bracts, arranged in elongated spiciform terminal racemes up to 36 cm long; bracts 4–5 mm long, truncate but produced dorsally into an acute setose apex, with or without a terminal fringe of short setae up to 1 mm long; pedicels red-brown, 6–7 mm long, glabrous. Male flowers not seen. Hermaphrodite flowers heterostylous, long-styled flowers not seen; perianth yellowish-green, glabrous, 5-lobed; tube 2–3 mm long; lobes 3–4 mm long, oblong.
    Filaments
    Filaments 0.3–3.5 mm long, filiform and flattened toward the base; anthers orange, 0.5–0.55 × 0.4–0.45 mm, oblong
    Ovary
    Ovary 3.4 × 2.3 mm, oblong; styles c. 1 mm long
    Ecology
    Clay sandy soils in dry river margins; 250–700 m.
    Distribution
    Malawi ZAM E, MAL S, MOZ N Zambia Mozambique Also in southern Tanzania and Angola.
    Pistil
    Ovary 3.4 × 2.3 mm, oblong; styles c. 1 mm long.
    Hermaphrodite
    Ovary 3.4 × 2.3 mm, oblong; styles c. 1 mm long. Filaments 0.3–3.5 mm long, filiform and flattened toward the base; anthers orange, 0.5–0.55 × 0.4–0.45 mm, oblong. Hermaphrodite flowers heterostylous, long-styled flowers not seen; perianth yellowish-green, glabrous, 5-lobed; tube 2–3 mm long; lobes 3–4 mm long, oblong.
    Fruits
    Nut 8–10 mm across, trigonous, with a spine on each angle; spines 2–3 mm long, pointing somewhat downwards. Nut 8–10 mm across, trigonous, with a spine on each angle; spines 2–3 mm long, pointing somewhat downwards.
    Male
    Male flowers not seen.
    Stamens
    Filaments 0.3–3.5 mm long, filiform and flattened toward the base; anthers orange, 0.5–0.55 × 0.4–0.45 mm, oblong.
    [FTEA]

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

    Habit
    A stout perennial (? a bush).
    Stem
    Stems glabrous or with scattered papillae.
    Ocrea
    Ocreae 0.5–2 cm. long, brown, ± glabrous, truncate with a terminal fringe of 7–9 setae 1–1.3 mm. long.
    Leaves
    Leaves petiolate, glabrous, large for the genus, 7.5–10.5 × 4.5–5.5 cm., entire or with a slightly wavy edge, broadly obovate to broadly ovate, apically obtuse (or shortly acuminate) to rounded, basally long-narrowed and decurrent to the petiole.
    Petiole
    Petioles 1–2 cm.
    Inflorescences
    Inflorescence elongated, up to 36 cm. long.
    Bracts
    Bracts 4–5 mm. long, up to 4 cm. apart, truncate but dorsally produced, with or without a terminal fringe of short setae up to 1 mm. long.
    Pedicel
    Pedicels glabrous, red, exceeding the bracts by 2.5–3 mm.
    Flowers
    Flowers 2 (?–4) together.
    Tepal
    Tepals 3–4 mm. long, oblong.
    Stamens
    Stamens almost equalling the tips of the tepals; anthers orange.
    Style
    Styles not seen.
    Fruits
    Very immature fruit with three protuberances on the angles, these probably being rudimentary prickles.
    Figures
    Fig. 5/1 and 2.
    Habitat
    No information available; about 1200 m.
    Distribution
    T7

    Distribution

    Native to:

    Angola, Malawi, Tanzania, Zambia, Zimbabwe

    Oxygonum buchananii (Dammer) J.B.Gillett appears in other Kew resources:

    Date Reference Identified As Barcode Type Status
    May 10, 1956 Buchanan, J [550], Malawi K000244062 lectotype

    First published in Kew Bull. 8: 83 (1953)

    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.
    • Graham, R.A. (1958). Flora of Tropical East Africa, Polygonaceae: 1-40.

    Literature

    Flora Zambesiaca
    • F.T.E.A., Polygonaceae: 28 (1958).
    • Kew Bull. 12: 152 (1957)
    • Kew Bull. 8: 83 (1953).
    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.
    Flora of Tropical East Africa
    • Gillett in Kew Bulletin 1953: 83 (1953).

    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

    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