The Asclepiadoideae are a subfamily of plants in the family Apocynaceae. Formerly, it was treated as a separate family under the name Asclepiadaceae, e.g. by APG II, and known as the milkweed family.[2][3]
There are 348 genera, with about 2,900 species. They are mainly located in the tropics to subtropics,[4] especially in Africa and South America.
The florally-advanced tribe Stapelieae within this family contains several relatively familiar stem succulent genera, such as Orbea, Huernia, Stapelia and Hoodia. They are remarkable for the complex mechanisms which they have developed for pollination, independently parallel to the unrelated Orchidaceae, such as the grouping of their pollen into pollinia. The "fragrance" (or odor) of the flowers, often called "carrion flowers", attracts flies, the chief pollinators for these plants. Additionally, the color, appearance and texture of the flowers often is thought to resemble decaying flesh or raw meat to further entice pollination by flies.
Many new hybrids have been formed due to the unique fertilization method of the flowers.
Taxonomy
Gilbert Thomas Burnett in 1835 is considered to be the first botanist to recognize a primary division of the family Apocynaceae using the name Asclepiadeae,[5] an ending now used for tribes rather than subfamilies. In 2014, Endress, Liede-Schumann and Meve recognised five tribes within the subfamily.[6] A molecular phylogenetic study in 2019 confirmed the distinctness of the five tribes, which were related as shown in the following cladogram:[7]
The assignment of genera to tribes is based on Endress, Liede-Schumann and Meve (2014),[6] with synonyms from Plants of the World Online as of December 2023[update].
These genera are not accepted within Asclepiadoideae by Endress et al. (2014),[6] but are accepted by Plants of the World Online. Tribal placements below are from GRIN-Global, where given.
Dalzielia Turrill – Marsdenieae (possible synonym of Marsdenia)[8]
Decanema Decne. – Asclepiadeae (possible synonym of Cynanchum)[9]
Dischidanthus Tsiang – Marsdenieae (possible synonym of Marsdenia)[10]
Gymnemopsis Costantin – Marsdenieae (possible synonym of Marsdenia)[11]
^Nazar, N.; Clarkson, J.J.; Goyder, D.; Kaky, E.; Mahmood, T. & Chase, M.W. (2019), "Phylogenetic relationships in Apocynaceae based on nuclear PHYA and plastid trnL-F sequences, with a focus on tribal relationships", Caryologia International Journal of Cytology, Cytosystematics and Cytogenetics, 72 (1): 55–81, doi:10.13128/cayologia-251
