Rapicactus
Rapicactus is a genus of cactus in the tribe Cacteae, subfamily Cactoideae. It has been synonymized with Turbinicarpus but molecular phylogenetic studies have supported its monophyly and separation from that genus.[1]
| Rapicactus | |
|---|---|
 | |
| Rapicactus zaragosae | |
Scientific classification  | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Order: | Caryophyllales |
| Family: | Cactaceae |
| Subfamily: | Cactoideae |
| Tribe: | Cacteae |
| Genus: | Rapicactus Buxb. & Oehme |
| Type species | |
| Rapicactus subterraneus | |
| Species | |
|
See text. | |
Taxonomy
The genus Rapicactus was proposed in 1942 by Buxbaum and Oehme.[2] It was characterized by having thick roots with a constriction above forming a neck. However, most subsequent treatments sank the genus into a broadly circumscribed genus Turbinicarpus. The circumscription of Turbinicarpus has been described as "remarkably unstable", with species regularly transferred to other genera.[1] The broad circumscription of Turbinicarpus was recognized as polyphyletic by Hunt in 2016.[3] A phylogenetic study published in 2019 showed that a monophyletic Rapicactus was sister to Acharagma, separated from a monophyletic Turbinicarpus:[1]
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Species
As of March 2022, Plants of the World Online accepted four species:[4]
| Image | Scientific name | Distribution |
|---|---|---|
 | Rapicactus beguinii (N.P.Taylor) Lüthy | NE. Mexico |
 | Rapicactus mandragora (Fric ex A.Berger) Buxb. & Oehme | Mexico (Durango, Coahuila, Nuevo León) |
 | Rapicactus subterraneus (Backeb.) Buxb. & Oehme | Mexico (Nuevo León, Tamaulipas, San Luis Potosí) |
| Rapicactus zaragosae (Glass & R.A.Foster) D.Donati | Mexico (Nuevo León, Tamaulipas) |
References
- Vázquez-sánchez, Monserrat; Sánchez, Daniel; Terrazas, Teresa; De La Rosa-Tilapa, Alejandro & Arias, Salvador (2019), "Polyphyly of the iconic cactus genus Turbinicarpus (Cactaceae) and its generic circumscription", Botanical Journal of the Linnean Society, 190 (4): 405–420, doi:10.1093/botlinnean/boz027
- "Rapicactus Buxb. & Oehme", International Plant Names Index (IPNI), Royal Botanic Gardens, Kew; Harvard University Herbaria & Libraries; Australian National Botanic Gardens, retrieved 2022-03-05
- Hunt, D.R. (2016), CITES Cactaceae checklist (3rd ed.), Kew: Royal Botanic Gardens and D. Hunt, ISBN 978-0-9933113-2-1
- "Rapicactus Buxb. & Oehme", Plants of the World Online, Royal Botanic Gardens, Kew, retrieved 2022-03-07