Wigginsia Porter (1964: 210)

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 : 162

8. Wigginsia Porter (1964: 210)

Type (designated by Porter 1964: 211):— Wigginsia corynodes ( Pfeiffer 1837: 55) D.M. Porter (1964: 211) .

Species richness:— Wigginsia includes 5 species ( Hunt et al. 2006).

General distribution:— Wigginsia is geographically restricted to southern Brazil, Uruguay and Argentina, in Rio Grande do Sul, four species were found in the Pampa Biome.

Distribution in Santa Maria river basin:— Three species were found, i.e. Wigginsia langsdorffii (Lehmann 1826: 17) D.M. Porter (1964: 211) ( Fig. 3K ), W. sellowii ( Link & Otto 1827: 425) F. Ritter (1979: 196) ( Fig. 3J ), and W. turbinata (Arechavaletae 1905: 235) D.M. Porter (1964: 211) ( Fig. 3L ), associated with rocky outcrops and saxicolous vegetation. They are plants of globular to cylindrical habit of 6 to 20 cm in diameter, densely tomentose in the apex, with tuberculated ribs, bell-shaped yellow flowers approximately 5 cm in length, fruits (glabrous) pink or red, hidden by the tom, devoid of trichomes or bristles. Depending on the species, flowering begins in October–December, bearing fruit soon after.

In the SMRB all species found are endemic to the Pampa ( Table 2 ) except for four that are also common to the Atlantic forest. Species of restricted distribution are Frailea albifusca , F. lepida , F. mammifera , F. erythracantha , Parodia arnostiana , P. curvispina , and P. ritteriana , which have populations located only in sedimentary and volcanic outcrops, respectively, within the study region, which proves the need for conservation and a management plan for the species’ occurrence areas.

The floristic diversity of the family is intrinsically related to the edaphic and climatic conditions provided by the stony springs in the Santa Maria River Basin, which constitute a favorable microclimate of intense luminosity, heat and humidity so that species adapted to xeromorphy such as Cactaceae develop in this region.

Regarding the populations found, it is noted that there is a lack of knowledge about the conservation of species, especially when there is mining in their areas of occurrence, it has been found in the literature that of the 29 species occurring in SMRB, 9 species are critically endangered. (CR), 9 endangered (EN) and 6 are vulnerable (VU).

Figures

FIGURE 3. A) Opuntia megapotamica (orange flowers). B) Parodia arnostiana (yellow flowers). C) P. herteri (pink flowers). D) P. linkii (yellow flower). E) P. mammulosa (yellow flower). F) P. nothorauschii. G) P. ottonis(flores yellow flower). H) P. ritteriana(yellow flower). I) P. tenuycilindrica. J) Wigginsiasellowii (yellow flower). K) W. langsdorffii (pale-yellow flower). L) W. turbinata (yellow flower). Pictures by A. S. Oliveira.