Aylostera
Aylostera, is a genus of cactus, native to central Bolivia and north western Argentina. Aylostera was formerly sunk into a broadly circumscribed genus Rebutia, but molecular phylogenetic studies from 2007 onwards showed that when defined in this way, Rebutia was not monophyletic, leading to the resurrection of Aylostera. A 2023 classification of the tribe Cereeae placed it as the only genus in the subtribe Aylosterinae. It was formerly placed in the subtribe Rebutiinae.
Description
Aylostera species are small cacti with globular stems. The stems may or may not have ribs; this feature can vary even within a species. Their flowers are of various colours. A key feature that distinguishes Aylostera from Rebutia is that the pericarpels and receptacles are hairy, rather than glabrous.Taxonomy
The genus Aylostera was erected by Carlo Luigi Spegazzini in 1923. A historical summary of the treatment of Aylostera and related genera published in 2011 showed how in succession it was recognized, sunk into Rebutia, and then resurrected to include a large part of Rebutia. A phylogenetic study in 2016 using both molecular and morphological characters confirmed that Aylostera was monophyletic and distantly related to the clade that contains the type species of Rebutia, thus justifying recognizing it as a separate genus. The separate status of Aylostera is accepted by Plants of the World Online, as of 2024.In a 2023 classification of the tribe Cereeae, it was placed as the only genus in the subtribe Uebelmanniinae, having formerly been placed in the subtribe Rebutiinae.
Species
The number of species accepted in Aylostera varies considerably. The 2016 study of the genus accepted only nine species, including a very broadly circumscribed Aylostera deminuta., Plants of the World Online accepted 26 species:| Image | Scientific name | Distribution |
| Aylostera albiflora Backeb. | Bolivia. | |
| Aylostera albopectinata Mosti & Papini | Bolivia. | |
| Aylostera atrovirens Mosti & Papini | Bolivia to Argentina | |
| Aylostera deminuta Backeb. | Bolivia to Argentina | |
| Aylostera einsteinii Mosti & Papini | Bolivia to Argentina | |
| Aylostera fiebrigii Backeb. | Bolivia to Argentina | |
| Aylostera flavistyla Mosti & Papini | Bolivia | |
| Aylostera fusca Mosti & Papini | Bolivia. | |
| Aylostera heliosa Mosti & Papini | Bolivia. | |
| Aylostera hoffmannii Mosti & Papini | Bolivia to Argentina | |
| Aylostera kupperiana Backeb. | Bolivia | |
| Aylostera leucanthema Mosti & Papini | Bolivia | |
| Aylostera malochii Ritz | Bolivia. | |
| Aylostera mamillosa Mosti & Papini | Bolivia | |
| Aylostera mandingaensis R.Wahl & Jucker | Bolivia. | |
| Aylostera muscula Backeb. | Bolivia | |
| Aylostera narvaecense Cárdenas | Bolivia | |
| Aylostera nigricans Mosti & Papini | Argentina | |
| Aylostera perplexa Mosti & Papini | Bolivia. | |
| Aylostera pseudominuscula Speg. | Bolivia to Argentina | |
| Aylostera pulvinosa Backeb. | Bolivia | |
| Aylostera pygmaea Mosti & Papini | Bolivia to Argentina | |
| Aylostera spinosissima Backeb. | Bolivia. | |
| Aylostera steinmannii Backeb. | Bolivia to Argentina | |
| Aylostera tarvitaensis Mosti & Papini | Bolivia. | |
| Aylostera tuberosa Backeb. | Bolivia. |