e-Key v3 - Buttonia
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Interactive keys to the identification of seed plants of southern Africa using keys based on plant morphology.

Scrophulariaceae - Rhinanthoideae - Buchnereae - Buttonia McKen ex Benth.

Description :

  • Perennial, slender, trailing or scrambling shrubs, hemiparasitic on roots; stems flexible, much branched, somewhat woody
  • Leaves opposite, petiolate, ± ovate in outline, dentate to pinnatifid or pinnatisect, coriaceous
  • Flowers solitary, axillary, pedicellate, bracteate and bibracteolate
  • Bracts small, deciduous; bracteoles opposite, subsessile just below calyx, deciduous
  • Calyx tubular, (4)5-lobed, somewhat leathery, inflated in fruit; tube ± campanulate or urceolate, 10-veined; lobes ovate, spreading, shorter than tube
  • Corolla tubular, 5-lobed, slightly irregular; tube narrow at base, inflated and ± funnel-shaped above, somewhat curved, with wide throat; limb spreading; lobes rounded, shorter than tube, subequal but posterior pair smallest, interior in bud
  • Stamens 4, didynamous, included, glabrous; upper pair arising in lower part of expanded portion of corolla tube; lower pair arising lower down, in upper part of narrow portion of tube; filaments linear; anthers connivent in pairs, bithecate or unithecate by abortion: upper stamens with one theca empty and vermiform, lower stamens with empty theca absent; staminodes 0
  • Ovary bilocular, globose, glabrous; ovules many per locule; style filiform, curved above, exserted; stigma obscurely 2-lobed
  • Fruit a globose, glabrous, loculicidal capsule, enclosed in enlarged, persistent calyx
  • Seeds many, conical-cylindrical, truncate at both ends; testa reticulate

Nomenclature:

  • Buttonia McKen ex Benth.
    • Bentham: 63, t. 1080 (1871)
    • Hiern: 384 (1904)
    • Hemsley & Skan: 439 (1906)
    • Hennessy: t. 1815 (1980)
    • Visser: 82, 157, tt. 148-152 (1981)
    • Philcox: 141 (1990)

Distribution & Notes:

  • Global : Species 3, tropical and southern Africa
  • Southern Africa : Species 2: Buttonia natalensis McKen ex Benth. and B. superba Oberm., Northern Province, Mpumalanga, Swaziland and KwaZulu-Natal

References:

  • BENTHAM, G. 1871. Buttonia natalensis . Hooker's Icones Plantarum 11
  • HEMSLEY, W.B. & SKAN, S.A. 1906. Scrophulariaceae . Flora of tropical Africa 4
  • HENNESSY, E.F. 1980. Buttonia natalensis . Flowering Plants of Africa 46
  • HIERN, W.P. 1904. Scrophulariaceæ . Flora capensis 4,2
  • PHILCOX, D. 1990. Scrophulariaceae . Flora zambesiaca 8,2
  • VISSER, J. 1981. Scrophulariaceae and Orobanchaceae . South African parasitic flowering plants . Juta, Cape Town