Frailea Britton & Rose (1922: 208)

Oliveira, Anabela Silveira De, Pontes, Rodrigo Corrêa, Robaina, Luis Eduardo De Souza & Trentin, Romário, 2022, The Cactaceae family in the Santa Maria river basin (Rio Grande do Sul, Brazil), Phytotaxa 542 (2), pp. 153-166 : 160-161

3. Frailea Britton & Rose (1922: 208)

Type (designated by Britton & Rose 1922: 210):— Frailea cataphracta Britton & Rose.

Species richness:— Frailea comprises 19 species according to Gerloff (2001). Twelve are endemic, recognized only for Rio Grande do Sul State (Pontes et al. 2018).

General distribution:— Frailea has a restricted geographical distribution to southern Brazil, Paraguay, Uruguay, southeastern Bolivia, and northeast Argentina.

Distribution in Santa Maria river basin:— In SMRB occur nine species, Frailea albifusca , ( Fig. 2C and Fig. 2F ), F. castanea Backeberg (1936: 415) ( Fig. 2D ), F. lepida Buining & Brederoo (1973: 106) , ( Fig. 2E ), F. mammifera , ( Fig. 2G ), F. pumila ( Lemaire 1838: 21) Britton & Rose (1922: 209) ( Fig. 2H ), F. pygmaea ( Spegazzini 1905: 497) Britton & Rose (1922: 210) ( Fig. 2I ), F. erythracantha R.Pontes, A.S.Oliveira & Deble (2018: 202) ( Fig. 2J ), in the study area, these species usually grow on rocky outcrops.

Morphologic notes:— They are tiny plants less than 4 cm in diameter, sometimes solitary, globular to cylindrical. Undeveloped ribs and very small straight or curved thorns. Flowers very ephemeral, l cleistogamous or casmogamous, yellow or cream-yellow, dense woolly floral bracts and many bristles. Dried fruit with many seeds up to 1.5 cm long. They usually bloom in summer and fruit soon after.

Figures

FIGURE 2. A) Cereus hildmaninanus (whitish-pink flowers). B) Echinopsis oxygona (pink flowers). C) Frailea albifusca. D) Frailea castanea. E) Frailea albifusca.F) Frailea lepida.G) Frailea mammifera. H) Frailea pumila. I) Frailea pygmaea.J) Frailea erythracantha K) Gymnocalycium denudatum (white flowers). L) Gymnocalycium uruguayense (yellow flowers). Pictures by A. S. Oliveira.