Frailea

Frailea
Frailea pumila
Scientific classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Order: Caryophyllales
Family: Cactaceae
Subfamily: Cactoideae
Tribe: Fraileeae
Genus: Frailea
Britton & Rose
Type species
Frailea cataphracta
Species

See text

Frailea is a genus of globular to short cylindrical cacti native to South America.

Description

They are characterized by low-growing, flattened-spherical to short-cylindrical stems that often form multiple shoots, though sometimes grow solitary. These stems have weakly developed ribs and tubercles, adorned with small spines. The short, funnel-shaped flowers emerge from the tip of the shoot. They are notable for their limited opening, often blooming only briefly during the day. A significant characteristic of most Frailea species are cleistogamous, where flowers self-pollinate and produce seeds without ever opening. This occurs because the anthers develop in contact with the stigma, allowing for self-fertilization within the closed bud. Cleistogamy is believed to be an adaptation to protect against adverse weather conditions that could impede pollination, especially during their summer flowering period which coincides with significant rainfall. The areoles on the pericarpel and flower tube are densely covered with woolly hairs and bristles. The fruits are thin-walled, dry, and packed tightly with seeds. They may retain a persistent floral remnant and can open irregularly or remain indehiscent. The seeds, measuring up to 1.5 millimeters in length, are broadly ovate or cap-shaped.[1]

Distribution

Frailea species are cacti typically found in South America, with a distribution across northeastern Argentina, eastern Bolivia, Colombia, southern Brazil, Paraguay, and Uruguay.

Species

Species accepted by the Plants of the World Online as of October 2022:[2]

Image Scientific name Distribution
Frailea alexandri Metzing Paraguay.
Frailea altasensis Prestlé Brazil (Rio Grande do Sul)
Frailea amerhauseri Prestlé Bolivia (Santa Cruz).
Frailea buenekeri W.R.Abraham Brazil (Rio Grande do Sul)
Frailea castanea Backeb. Argentina, Brazil and Uruguay
Frailea cataphracta (Dams) Britton & Rose Paraguay
Frailea chiquitana Cárdenas Bolivia
Frailea curvispina Buining & Brederoo Brazil
Frailea diersiana Schädlich Bolivia.
Frailea erythracantha R.Pontes, A.S.Oliveira & Deble Brazil (Rio Grande do Sul)
Frailea fulviseta Buining & Brederoo Brazil
Frailea gracillima (Lem.) Britton & Rose Brazil, Paraguay, and Uruguay
Frailea mammifera Buining & Brederoo Bolivia and Argentina
Frailea phaeodisca (Speg.) Backeb. & F.M.Knuth Brazil and Uruguay
Frailea piltzii C.A.L.Bercht & Schädlich Paraguay
Frailea pumila (Lem.) Britton & Rose Brazil, Argentina, and Uruguay
Frailea pygmaea (Speg.) Britton & Rose Bolivia, Argentina, and Uruguay.
Frailea schilinzkyana (F.Haage ex K.Schum.) Britton & Rose Brazil to Argentina.
Frailea stockingeri Prestlé Brazil (Rio Grande do Sul)

Taxonomy

The genus Frailea was first described in 1922 by Nathaniel Lord Britton and Joseph Nelson Rose. It is named in honor of Manuel Fraile, who managed the cactus collection at the United States Department of Agriculture.[3] The type species is Frailea cataphracta. They were first classified in the genus Echinocactus. In 2016, the monotypic tribe Fraileeae was established within the subfamily Cactoideae for this monophyletic genus.[4][5]

References

  1. ^ Anderson, Edward F.; Eggli, Urs (2005). Das grosse Kakteen-Lexikon (in German). Stuttgart (Hohenheim): Ulmer. p. 299-303. ISBN 3-8001-4573-1.
  2. ^ "Frailea Britton & Rose". Plants of the World Online. Royal Botanic Gardens, Kew. 2022. Retrieved 9 October 2022.
  3. ^ Burkhardt, Lotte (2018-06-06). Verzeichnis eponymischer Pflanzennamen - Erweiterte Edition. Index of Eponymic Plant Names - Extended Edition. Index de Noms éponymiques des Plantes - Édition augmentée. Botanic Garden and Botanical Museum Berlin, Freie Universität Berlin. doi:10.3372/epolist2018. ISBN 978-3-946292-26-5. Retrieved 2026-01-04.
  4. ^ "P. R. Brice Chéron Fraileeae B. P. R. Chéron, Tribus nova. In: International Cactus Adventures. Band 55, 2016, S. 111–112" (PDF). Retrieved 2026-01-04.
  5. ^ Korotkova, Nadja; Aquino, David; Arias, Salvador; Eggli, Urs; Franck, Alan; Gómez-Hinostrosa, Carlos; Guerrero, Pablo C.; Hernández, Héctor M.; Kohlbecker, Andreas; Köhler, Matias; Luther, Katja; Majure, Lucas C.; Müller, Andreas; Metzing, Detlev; Nyffeler, Reto; Sánchez, Daniel; Schlumpberger, Boris; Berendsohn, Walter G. (2021-08-31). "Cactaceae at Caryophyllales.org – a dynamic online species-level taxonomic backbone for the family". Willdenowia. 51 (2). doi:10.3372/wi.51.51208. ISSN 0511-9618. Retrieved 2026-01-04.
  • Media related to Frailea at Wikimedia Commons
  • Data related to Frailea at Wikispecies
  • Frailea website
  • Cactiguide Frailea