Distephanus

{{Short description|Genus of flowering plants}}

{{Automatic taxobox

|image = African veined white 2017 07 02 0194.jpg

|image_caption = D. angulifolius flowers being pollinated by the African veined white butterfly

|display_parents = 3

|parent_authority = (S.C.Keeley & H.Rob.) H.Rob. & V.A.Funk (2024)

|taxon = Distephanus

|authority = Cass. (1819)

|type_species = Distephanus populifolius

|type_species_authority = (Lam.) Cass.Distephanus At: Index Nominum Genericorum In: Regnum Vegetabile. (see External links below).

|synonyms_ref = [https://archive.today/20141119010238/http://dixon.iplantcollaborative.org/CompositaeWeb/default.aspx?Page=NameDetails&TabNum=0&NameId=0febf4f4-3161-480e-b85f-068426c96b32 Flann, C (ed) 2009+ Global Compositae Checklist ]

|synonyms =

• Antunesia O.Hoffm. (1893)
• Gongrothamnus Steetz (1864)
• Newtonia O.Hoffm. (1892), nom. illeg.

}}

Distephanus is a genus of flowering plants in the family Asteraceae.Harold E. Robinson. 2007. "Vernonieae" pages 149-174. In: Klaus Kubitzki (series editor); Joachim W. Kadereit and Charles Jeffrey (volume editors). The Families and Genera of Vascular Plants volume VIII. Springer-Verlag: Berlin; Heidelberg, Germany. {{ISBN|978-3-540-31050-1}} It is described by American botanist Harold E. Robinson as having over 40 species and by David Mabberley as having only 34 species.David J. Mabberley. 2008. Mabberley's Plant-Book third edition (2008). Cambridge University Press: UK. {{ISBN|978-0-521-82071-4}} These sources differ sharply in their description of the range of the genus. Robinson has it ranging throughout Africa and occurring also in India and China. Mabberley has it restricted to southeast Africa, Madagascar, and Mauritius. Plants of the World Online accepts 44 species native to sub-Saharan Africa, Madagascar, and south-central China.{{cite web|url=https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:8653-1 |title=Distephanus Cass. |website = |accessdate=30 May 2024}}

The genus Distephanus consists of trees, shrubs, and vines. The leaves are often trinervate. The flowers are in terminal inflorescences and are usually yellow. The anthers have an appendage called a tail. The base of the style is enlarged.

The name Distephanus is derived from Greek and means "two crowns", a reference to the two whorls of bristles that form the pappus.Umberto Quattrocchi. 2000. CRC World Dictionary of Plant Names volume II:822. CRC Press: Boca Raton; New York; Washington, DC;, USA. London, UK. {{ISBN|978-0-8493-2676-9}}. (vol. 2). (see External links below).

The genus Distephanus was established by Alexandre de Cassini in 1817.Alexandre H.G. de Cassini. 1817. Bulletin des Sciences, par la Société Philomatique de Paris. (1817):151. Cassini described the type species, Distephanus populifolia in 1819.Alexandre H.G. de Cassini. 1819. Dictionnaire des Sciences Naturelles, ... Strasbourg. edition 2. (F. Cuvier). 19:361. This species had originally been named Conyza populifolia by Jean-Baptiste Lamarck in 1786.Jean-Baptiste Lamarck. 1786. Encyclopedie Methodique. Botanique ... Paris. 2(1):87.

Distephanus has usually been placed in the tribe Vernonieae, but the results of some molecular phylogenetic studies of DNA sequences have cast doubt upon this placement. In one classification of Asteraceae, it was placed in a tritomy consisting of Distephanus, Moquinieae, and Vernonieae.Vicki A. Funk, Alfonso Susanna, Tod F. Stuessy, and Randall J. Bayer. 2009. Systematics, Evolution and Biogeography of the Compositae. IAPT (International Association for Plant Taxonomy). {{ISBN|978-3-9501754-3-1}} (see External links below). In 2024 Gostel et al. concluded that the genus belonged in its own tribe, Distephaneae.M R Gostel, Benoit Loeuille, Mariana Henriques Santana, Carol L Kelloff, Raymund Chan, Ana Rita Giraldes Simões, Isabel Larridon, Vicki A Funk, Molecular phylogenetics of Distephanus supports the recognition of a new tribe, Distephaneae (Asteraceae), Botanical Journal of the Linnean Society, 2024;, boae025, https://doi.org/10.1093/botlinnean/boae025

Distephanus differs from (other) genera in Vernonieae in having yellow flowers as well as in other characters that are less obvious.Harold E. Robinson. 1986. "Trinervate leaves, yellow flowers, tailed anthers, and pollen variation in Distephanus Cassini (Vernonieae: Asteraceae)". Proceedings of the Biological Society of Washington 99(3):493-501.