Duvalia

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Duvalia
Duvalia corderoyi.jpg
Duvalia corderoyi
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Asterids
Order: Gentianales
Family: Apocynaceae
Subfamily: Asclepiadoideae
Tribe: Ceropegieae
Genus: Duvalia
Haw. 1812 not Bonpland 1813 nor Nees 1818

Duvalia is a succulent plant genus in the subfamily Asclepiadoideae, in the family Apocynaceae (dogbane).

Contents

The genus was first described in 1812, named after the French physician and botanist Henri-Auguste Duval (1777-1814). [1]

Description

The rare Duvalia parviflora has smooth "potato-shaped" stems and tiny, cream-coloured flowers. Duvalia parviflora 01.jpg
The rare Duvalia parviflora has smooth "potato-shaped" stems and tiny, cream-coloured flowers.
Duvalia elegans, the type species of the genus, showing its wider, triangular flower lobes. Duvalia caesp elegans - flowers 2 - Copy.jpg
Duvalia elegans , the type species of the genus, showing its wider, triangular flower lobes.
The hairy flowers of Duvalia vestita (Duvalia caespitosa subsp. vestita). Duvalia caespitosa vestita - Malgas-Infanta - Copy.jpg
The hairy flowers of Duvalia vestita (Duvalia caespitosa subsp. vestita).
Duvalia caespitosa, one of the commonest and most widespread species, from the west of South Africa Duvalia caespitosa.jpg
Duvalia caespitosa , one of the commonest and most widespread species, from the west of South Africa

Vegetative

The Duvalia species are succulent, perennial plants with low, planar growth. The stems 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 stems of some species, such as the rounded Duvalia parviflora , are distinctive, and these species can be identified even when not in flower. However the stems are very variable, and most Duvalia species can only be distinguished from each other when the flower is seen.

The stems are superficially very similar to those of the related genus Piaranthus , and the two are often confused when not in flower. In cross-section, Duvalia stems are sometimes five or six sided ( Piaranthus stems are always four-sided in cross-section). To accurately distinguish them however, it is necessary to examine the flowers.

Floral

The distinctive flowers are on long, bare stalks, which grow from the base of the stems.

Each flower has five thin, elongated petal-like lobes, radiating in a star-shape, from a central raised disk or annulus.

The colour of most species flowers is shades of reddish brown, except for those of the rare Duvalia parviflora which are cream-coloured. 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.

Distribution

It occurs in southern Africa. The majority of the species are restricted to the western part of South Africa & Namibia, with the greatest number of species occurring in the Great Karoo region, on the edge of the winter rainfall area. Only one species, Duvalia polita extends further east, and as far north into tropical Africa as Malawi and Zambia. [2] [3]

Four species, occurring on the other side of the continent on the verges of the Red Sea, were formerly included in the genus Duvalia. However phylogenetic studies have shown them to be relatively unrelated to the rest of the genus, and more closely related to genus Ballyanthus Bruyns. [4]

Species [5]
  1. Duvalia anemoniflora (Deflers) R.A. Dyer & Lavranos - Arabia
  2. Duvalia angustiloba N.E.Br. - South Africa
  3. Duvalia caespitosa (Masson) Haw. - South Africa
  4. Duvalia corderoyi (Hook.f.) N.E.Br. - South Africa
  5. Duvalia eilensis Lavranos - Somalia
  6. Duvalia elegans (Masson) Haw. - Cape Province
  7. Duvalia galgallensis Lavranos - Somalia
  8. Duvalia gracilis Meve - Cape Province
  9. Duvalia immaculata (C.A.Lückh.) M.B.Bayer ex L.C.Leach - South Africa
  10. Duvalia maculata N.E.Br. - South Africa
  11. Duvalia modesta N.E.Br. - South Africa
  12. Duvalia parviflora N.E.Br. - Cape Province
  13. Duvalia pillansii N.E.Br. - Cape Province
  14. Duvalia polita N.E.Br. - South Africa
  15. Duvalia pubescens N.E.Br. - Cape Province
  16. Duvalia somalensis Lavranos - Somalia
  17. Duvalia sulcata N.E.Br. - Arabia
  18. Duvalia velutina Lavranos - Saudi Arabia
  19. Duvalia vestita Meve - Cape Province
formerly included [5]

transferred to Mannia

Related Research Articles

<span class="mw-page-title-main">Asclepiadoideae</span> Subfamily of plants

The Asclepiadoideae are a subfamily of plants in the family Apocynaceae. Formerly, they were treated as a separate family under the name Asclepiadaceae, e.g. by APG II, and known as the milkweed family.

<i>Hoodia</i> Genus of flowering plants

Hoodia is a genus of flowering plants in the family Apocynaceae, under the subfamily Asclepiadoideae, native to Southern Africa.

<i>Stapelia</i> Genus of plants

Stapelia is a genus of low-growing, spineless, stem succulent plants, predominantly from South Africa with a few from other parts of Africa. Several Asian and Latin American species were formerly included but they have all now been transferred to other genera. The flowers of certain species, most notably Stapelia gigantea, can reach 41 cm (16 inches) in diameter when fully open. Most Stapelia flowers are visibly hairy and generate the odor of rotten flesh when they bloom.

<i>Huernia</i> Genus of flowering plants

The genus Huernia consists of perennial, stem succulents from Eastern and Southern Africa and Arabia, first described as a genus in 1810.

<i>Larryleachia</i> Genus of plants

Larryleachia is a genus of stapeliad succulent flowering plants in the family Apocynaceae.

<i>Tridentea</i> Genus of plants

Tridentea is a genus of succulent plant in the family Apocynaceae, endemic to southern Africa.

<i>Edithcolea</i> Genus of flowering plants

Edithcolea is a monotypic genus with a single species Edithcolea grandis. Once classified in the family Asclepiadaceae, it is now in the subfamily Asclepiadoideae of the dogbane family Apocynaceae. It is native to Africa and to the Arabian Peninsula.

<i>Cynanchum viminale</i> Species of plant

Cynanchum viminale is a leafless succulent plant in the family Apocynaceae. The species is native to West Africa, the Indian Ocean and Western Pacific region. The species' natural range extends from South Africa throughout much of Africa and the Middle East to India, Indochina, Southern China, Indomalaya and into Meganesia. The species is also found on several Indian Oceans islands including Mauritius, Réunion and the Seychelles.

<i>Stapelianthus</i> Genus of plants

Stapelianthus is a genus of flowering plants in the family Apocynaceae, first described as a genus in 1933. The entire genus is endemic to Madagascar and is concentrated in the far south of the island.

<i>Fockea</i> Genus of flowering plants

Fockea is a genus of succulent scrubs native to Africa south of the equator. They are members of the Asclepiadoideae (milkweeds), a subfamily of the dogbane family Apocynaceae. Of the six recognized species, only the two most widely distributed extend north of southern Africa, with F. multiflora reaching as far north as Tanzania and F. angustifolia reaching to southern Kenya. Fockea are known as water roots, a reference to the bulbous caudex characteristic of most species, which is also edible in at least some species.

<i>Pseudolithos</i> Genus of plants

Pseudolithos is a genus of succulent flowering plants of the family Apocynaceae, indigenous to arid areas of Somalia, Yemen and Oman.

<i>Stapeliopsis</i> Genus of plants

Stapeliopsis is a genus of succulent plants in the family Apocynaceae, native to southern Africa.

<i>Echidnopsis</i> Genus of flowering plants

Echidnopsis is a genus of succulent, cactus-like plants in the family Apocynaceae, first described as a genus in 1871. They are native to eastern Africa and the Arabian Peninsula.

<i>Piaranthus</i> Genus of flowering plants

Piaranthus is a succulent plant genus in the subfamily Asclepiadoideae, in the family Apocynaceae.

<i>Orbea</i> (plant) Genus of flowering plants

Orbea is a genus of flowering plants of the family Apocynaceae, first described as a genus in 1812. It is native to Africa and the Arabian Peninsula.

Notechidnopsis is a group of plants in the family Apocynaceae first described as a genus in 1985. It contains only one recognized species, Notechidnopsis tessellata, native to Cape Province in South Africa.

<i>Rhytidocaulon</i> Genus of flowering plants

Rhytidocaulon is a plant genus in the family Apocynaceae, first described in 1962. It is native to northeastern Africa and the Arabian Peninsula

<i>Duvalia elegans</i> Species of plant

Duvalia elegans is a small succulent plant species, in the family Apocynaceae. It is the type species of the genus Duvalia, and it is endemic to the Western Cape Province, South Africa.

<i>Duvalia vestita</i> Species of plant

Duvalia vestita is a small succulent plant species, in the family Apocynaceae, indigenous to the southernmost part of the Western Cape Province, South Africa.

References

  1. ↑ Haworth, Adrian Hardy. 1812. Synopsis Plantarum Succulentarum: cum descriptionibus, synonymis, locis, observationibus anglicanis, culturaque 44.
  2. ↑ Tropicos Duvalia
  3. ↑ Gibbs Russell, G. E., W. G. M. Welman, E. Retief, K. L. Immelman, G. Germishuizen, B. J. Pienaar, M. Van Wyk & A. Nicholas. 1987. List of species of southern African plants. Memoirs of the Botanical Survey of South Africa 2(1–2): 1–152(pt. 1), 1–270(pt. 2).
  4. ↑ P. Bruyns, C. Klak, P. Hanacek: Evolution of the stapeliads (Apocynaceae-Asclepiadoideae) - repeated major radiation across Africa in an Old World group. Molecular Phylogenetics and Evolution. 2014. v. 77, no. 1, p. 251--263. ISSN 1055-7903.
  5. 1 2 The Plant List, Duvalia

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

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