e-Key <span id="jodit_selection_marker_1709299111751_44701617268660865" data-jodit_selection_marker="start" style="line-height: 0; display: none;"></span>v3 - E<span id="jodit_selection_marker_1709299111751_2263312371231856" data-jodit_selection_marker="end" style="line-height: 0; display: none;"></span>xacum
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Interactive keys to the identification of seed plants of southern Africa using keys based on plant morphology.

Gentianaceae - Exacum L.

Description:

  • Annual herbs, rarely perennial
  • Leaves entire
  • Flowers in dichotomous, terminal and axillary cymes
  • Calyx 4- or 5-lobed; lobes usually broadly winged
  • Corolla 4- or 5-lobed, blue, pink or white; tube short, broadly cylindrical
  • Stamens 4 or 5, arising below sinuses; anthers dehiscing by terminal pores or slits
  • Ovary 2-locular by intrusion of locular walls; style short; stigma capitate
  • Capsule 2-valved, globose; placenta appearing axile
  • Seeds many, minute
  • x = 17, 31 (9, 14, 15) (polyploidy)

Nomenclature:

  • Exacum L.
    • Linnaeus: 112 (1753)
    • Baker & Brown: 545 (1903)
    • Marais & Verdoorn: 211 (1963)
    • Klackenberg: 85 (1985)
    • Paiva & Nogueira: 8 (1990)

Distribution & Notes:

  • Global: Species 65, mainly in Madagascar, Socotra, Sri Lanka and S India, but also SE Asia, New Guinea and Australia, 2 on African continent
  • Southern Africa: Species 1: Exacum oldenlandioides (S.Moore) Klack., Northern Province and Mpumalanga

References:

  • BAKER, J.G. & BROWN, N.E. 1903. Gentianeae. Flora of tropical Africa 4,1
  • KLACKENBERG, J. 1985. The genus Exacum (Gentianaceae). Opera Botanica 84
  • LINNAEUS, C. 1753. Species plantarum. Laurentius Salvius, Stockholm
  • MARAIS, W. & VERDOORN, I.C. 1963. Gentianaceae. Flora of southern Africa 26
  • PAIVA, J.A.R. & NOGUEIRA, I. 1990. Gentianaceae. Flora zambesiaca 7,4