The Asclepiadoideae are a subfamily of flowering plants in the family Apocynaceae. Formerly, these plants together with those now in the Apocynaceae subfamilies Periplocoideae and Secamonoideae were treated as a separate family under the name Asclepiadaceae, e.g. by APG II, and known as the milkweed family.
They form a group of perennial herbs, twining shrubs, lianas or rarely trees but notably also contain a significant number of leafless stem succulents. The name comes from the type genus Asclepias (milkweeds).
There are 348 genera, with about 2,900 species. They are mainly located in the tropics to subtropics, 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, an ending now used for tribes rather than subfamilies. In 2014, Endress, Liede-Schumann and Meve recognised five tribes within the subfamily. A molecular phylogenetic study in 2019 confirmed the distinctness of the five tribes, which were related as shown in the following cladogram:
Tribes and genera
The assignment of genera to tribes is based on Endress, Liede-Schumann and Meve (2014), with synonyms from Plants of the World Online . A full revision of the section Marsdenieae was published by Liede-Schumann et al in 2022 and those additional genera have that citation.
Asclepiadeae
Araujia Brot. Asclepias L., including Aidomene Stopp, Odontostelma Rendle, Trachycalymma (K.Schum.) Aspidoglossum E.Mey. Aspidonepsis Nicholas Astephanus R.Br. Barjonia Decne. Blepharodon Decne. Calciphila Liede Calotropis R.Br. Cordylogyne E.Mey. Cynanchum L., including Adelostemma Hook.f., Glossonema Decne., Metaplexis R.Br., Pentarrhinum E.Mey., Seshagiria Ansari, Sichuania M.G.Gilbert Diplolepis R.Br. Ditassa R.Br. Fanninia Harv. Fischeria DC. Funastrum E.Fourn. Glossostelma Schltr. Gomphocarpus R.Br. Gonolobus Michx. Graphistemma (Champ. Gyrostelma E.Fourn. Hemipogon Decne. Holostemma R.Br. Hypolobus E.Fourn. Ibatia Decne. Jobinia E.Fourn. Kanahia R.Br. Lachnostoma Kunth Macroscepis Kunth Mahawoa Schltr. Margaretta Oliv. Matelea Aubl. Metastelma R.Br. Microloma R.Br. Minaria T.U.P.Konno Miraglossum Kupicha Monsanima Liede Morrenia Lindl. Nautonia Decne. Nephradenia Decne. Odontanthera Wight Oncinema Arn. Orthosia Decne. Oxypetalum R.Br. Oxystelma R.Br. Pachycarpus E.Mey. Parapodium E.Mey. Pentacyphus Schltr., including Tetraphysa Schltr. Pentastelma Tsiang Pentatropis R.Br. Peplonia Decne. Pergularia L. Petalostelma E.Fourn. Phaeostemma E.Fourn. Pherotrichis Decne. Philibertia Kunth, including Mitostigma Decne. Pseudolachnostoma Morillo Raphistemma Wall. Rhyssostelma Decne. Rhytidostemma Morillo Rojasia Malme Schizoglossum E.Mey. Schizostephanus Hochst. Schubertia Mart. Scyphostelma Baill. Solenostemma Hayne Stathmostelma K.Schum. Stelmagonum Baill. Stenostelma Schltr. Tassadia Decne., including Stenomeria Turcz. Tweedia Hook. Tylodontia Griseb. Vincetoxicum Wolf, including Merrillanthus Chun, Oncostemma K.Schum., Rhyncharrhena F.Muell. Widgrenia Malme Woodia Schltr. Xysmalobium R.Br.
Ceropegieae
Anisotoma Fenzl Apteranthes J.C.Mikan Australluma Plowes Baynesia Bruyns Boucerosia Wight Brachystelma Sims Caralluma R.Br. Caudanthera Plowes Ceropegia L. Conomitra Fenzl Desmidorchis Ehrenb. Duvalia Haw. Duvaliandra M.G.Gilbert Echidnopsis Hook.f. Edithcolea N.E.Br. Emplectanthus N.E.Br. Heterostemma Wight Hoodia Sweet Huernia R.Br. Larryleachia Plowes Lavrania Plowes Leptadenia R.Br. Monolluma Plowes Neoschumannia Schltr. Notechidnopsis Lavranos Ophionella Bruyns Orbea Haw., including Orbeanthus L.C.Leach Orthanthera Wight Pectinaria Haw. Pentasacme Wall. Piaranthus R.Br. Pseudolithos P.R.O.Bally, including Anomalluma Plowes Quaqua N.E.Br. Rhytidocaulon P.R.O.Bally Richtersveldia Meve Riocreuxia Decne. Sisyranthus E.Mey. Socotrella Bruyns Stapelia L. Stapelianthus Choux Stapeliopsis Pillans Tavaresia Welw. Tridentea Haw. Tromotriche Haw. Whitesloanea Chiov.
Eustegieae Emicocarpus R.Br. Eustegia K.Schum. & Schltr.
Fockeeae Cibirhiza Bruyns Fockea Endl.
Marsdenieae
Anatropanthus Schltr. Anisopus N.E.Br. Asterostemma Decne. Campestigma Pierre Cionura Griseb. Cosmostigma Wight Dischidanthus Tsiang Dischidia R.Br. Dolichopetalum Tsiang Gongreos Rodda, Liede & Meve Gongronema (Endl.) Decne. Gongronemopsis S.Reuss, Liede & Meve Gunnessia P.I.Forst. Gymnema R.Br. Harmandiella Costantin Heynella Backer Hoya R.Br., including Cathetostemma Blume, Clemensiella Schltr. Jasminanthes Blume Leichhardtia R.Br. Lygisma Hook.f. Marsdenia R.Br. Oreosparte Schltr. Papuahoya Rodda & Simonsson Pycnorhachis Benth. Rhyssolobium E.Mey. Ruehssia H.Karst. ex Schltdl. Sarcolobus R.Br., including Quisumbingia Merr. Sicyocarpus Bojer Stephanotis Thouars, including Dregea E.Mey., Wattakaka Hassk. Stigmatorhynchus Schltr. Telosma Coville Treutlera Hook.f.
Other genera These genera are not accepted within Asclepiadoideae by Endress et al. (2014), but are accepted by Plants of the World Online. Tribal placements below are from GRIN-Global, where given.
Dalzielia Turrill - no molecular evidence but kept separate from Marsdenia in Marsdenieae. Decanema Decne. – Asclepiadeae (possible synonym of Cynanchum) Gymnemopsis Costantin - no molecular evidence but kept separate from Pseudosarcolobus and Harmandiella in Marsdenieae. Kerbera E.Fourn. – Asclepiadeae Periglossum Decne. – Asclepiadeae Polystemma Decne., including Microdactylon – Asclepiadeae (possible synonym of Matelea) Ptycanthera Decne. – Asclepiadeae (possible synonym of Matelea) Schistonema Schltr. – Asclepiadeae (possible synonym of Tweedia) Vailia Rusby – Asclepiadeae (possible synonym of Blepharodon)
References
External links
Stapeliads.info Field Manual for Seed Collectors, Royal Botanic Gardens, Kew Asclepiad info from ig-ascleps.org Asclepiadaceae Family The Genera of Asclepiadoideae, Secamonoideae and Periplocoideae (Apocynaceae) Asclepiadaceae in BoDD – Botanical Dermatology Database