e-Key <span id="jodit_selection_marker_1709037445808_6492023829453295" data-jodit_selection_marker="start" style="line-height: 0; display: none;"></span>v3 - Duthiea<span id="jodit_selection_marker_1709037445808_2571084275645821" data-jodit_selection_marker="end" style="line-height: 0; display: none;"></span>strum
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Interactive keys to the identification of seed plants of southern Africa using keys based on plant morphology.

Iridaceae - Ixioideae - Duthieastrum M.P.de Vos

Description:

  • Deciduous perennial
  • Rootstock a globose corm rooting from below, basal in origin, tunics of fine, reticulate fibres
  • Stem subterranean, branched below ground
  • Leaves several, lower 2 or 3 cataphylls; foliage leaves unifacial, with a definite midrib, in a tight distichous fan, blades plane
  • Inflorescence subterranean, simple or branched, flowers 1 or 2 per branch; bracts membranous, concealed by leaves, inner slightly shorter than outer and notched apically
  • Flowers actinomorphic, hypocrateriform, yellow, unscented, with nectar from septal nectaries; perianth tube elongate, cylindric
  • Tepals subequal, spreading
  • Stamens symmetrically disposed, erect; filaments arising at mouth of tube; anthers exserted; pollen monosulcate, operculate, exine perforate
  • Ovary subterranean
  • Style filiform, exserted, branches slender, undivided and recurved
  • Capsules club-shaped, sterile and shortly tubular below, cartilaginous
  • Seeds globose, flattened at chalazal end, smooth, shiny, raphal vascular trace excluded
  • x = 10

Classification Notes:

  • The affinities of Duthieastrum lie with Tritonia or Sparaxis, both according well in vegetative appearance, corm tunics, and leaf anatomy. The leaves lack subepidermal sclerenchyma and the marginal epidermal cells hardly differ from those of the lamina. Some species of Tritonia have similar marginal epidermis while others have thickened, columnar marginal epidermal cells as do all species of Sparaxis

Nomenclature:

  • Duthieastrum M.P.de Vos
    • De Vos: 91 (1975)
    • De Vos: 139 (1999)
  • Duthiella M.P.de Vos
    • De Vos: 301 (1974), name illegitimate, not of Müll.Hal. ex Broth.

Distribution & Notes:

  • Southern Africa: Species 1, northern Karoo (Northern Cape)

Additional Notes:

  • The yellow flowers open in the afternoon and close shortly after dark each day

References:

  • DE VOS, M.P. 1974. Duthiella, 'n nuwe genus van die Iridaceae. Journal of South African Botany 40
  • DE VOS, M.P. 1975. 'n Nuwe naam vir Duthiella. Journal of South African Botany 41
  • DE VOS, M.P. 1999. Ixia, Tritonia, Crocosmia, Duthieastrum, Chasmanthe. Flora of southern Africa 7,2, fascicle 1