Duvalia

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Duvalia
Duvalia corderoyi
Scientific classification
Kingdom: Plantae
(unranked): Angiosperms
(unranked): Eudicots
(unranked): Asterids
Order: Gentianales
Family: Apocynaceae
Genus: Duvalia
Haw.

Duvalia is a plant genus in the tribe Stapeliae, milkweed subfamily Asclepiadoideae, in the family Apocynaceae (dogbane). The genus is named after the French physician and botanist Henri-Auguste Duval (1777-1814). It can be found on the Arabian peninsula, in tropical Africa and South Africa.

The Duvalia species are succulent, perennial plants with low, planar growth. The shoots are clavate, cylindrical to spherical, in cross-section four-, five-or six-edged, and to about 10 inches long. They can range from green, gray to mottled reddish in color. The flower stems are long and bare. The hermaphroditic flowers measure 1-5 cm in diameter, and have five parts. The crown is yellow ocher, brown, red to dark purple. The five corolla lobes are flat or folded along the middle nerve.

The genus was established in 1812 in Adrian Hardy Haworth's Synopsis Plantarum Succulentarum to include three species (S. caespitosa, S. elegans, and S. reclinata).

Species

Ulrich Meve and Focke Albers in 1990 divided the genus Duvalia into two sections, Duvalia and Arabica. They list 21 species, subspecies and varieties:

  • Duvalia sect. Duvalia
    • Duvalia angustiloba N.E.Br.
    • Duvalia caespitosa (Masson) Haw. : With two varieties:
      • Duvalia caespitosa var caespitosa
      • Duvalia caespitosa var compacta (Haw.) Meve
    • Duvalia corderoyi (Hook. f) NE Br.
    • Duvalia elegans (Masson) Haw.
    • Duvalia gracile Meve
    • Duvalia immaculata (CALückh.) MBBayer ex LCLeach
    • Duvalia maculata N.E.Br.
    • Duvalia modesta N.E.Br.
    • Duvalia parviflora N.E.Br.
    • Duvalia pillansii N.E.Br.
    • Duvalia polita N.E.Br.
    • Duvalia pubescens N.E.Br.
    • Duvalia vestita Meve
  • Duvalia sect. Arabica Meve & F.Albers
    • Duvalia eilensis Lavranos
    • Duvalia galgallensis Lavranos
    • Duvalia sulcata N.E.Br. : With three subspecies:
      • Duvalia sulcata subsp. sulcata
      • Duvalia sulcata subsp. seminuda (Lavranos) Meve
      • Duvalia sulcata subsp. somalensis (Lavranos) Meve
    • Duvalia velutina Lavranos

A dubious name: Duvalia anemoniflora (Deflers) RADyer. & Lavranos

References

Portions of this page were translated from the equivalent page on the German wikipedia accessed July 3, 2012


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