Rapicactus

Rapicactus
Rapicactus zaragosae
Scientific classification Edit this 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.

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]

Taxonomy

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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]

Three species of other genera

Acharagma

Rapicactus

Species of other genera

Species of other genera

Species

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As of May 2024, Plants of the World Online accepted four species:[4]

Image Scientific name Distribution
Rapicactus beguinii (N.P.Taylor) Lüthy NE. Mexico
Rapicactus booleanus (G.S.Hinton) D.Donati Mexico (Nuevo León)
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

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  1. ^ a b c 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
  2. ^ "Rapicactus Buxb. & Oehme", International Plant Names Index (IPNI), Royal Botanic Gardens, Kew; Harvard University Herbaria & Libraries; Australian National Botanic Gardens, retrieved 2022-03-05
  3. ^ Hunt, D.R. (2016), CITES Cactaceae checklist (3rd ed.), Kew: Royal Botanic Gardens and D. Hunt, ISBN 978-0-9933113-2-1
  4. ^ "Rapicactus Buxb. & Oehme", Plants of the World Online, Royal Botanic Gardens, Kew, retrieved 2022-03-07