During our 2013-2014 journey, on March 14, 2014, we dedicated ourselves to the ascent to Cerro Ayrampo, a mountain that is 2826m high, and dominates the village of Zudáñez, in the Chuquisaca Department, Bolivia. The site is known to Cactaceae enthusiasts for being the type locality of Sulcorebutia rauschii Gerhart Frank. In an attempt to find new populations, we didn't go up along the usual path, but we have scoured from the base, the different hills making up the mountain, and then climbed it vertically from the base to the main peak, on the southwest side, to find that the first groups of the species live only at 2800-2805m (A&M 1061, A&M 1062), just before the top (A&M 1063, A&M 1064), while the populations living near the path, that rises from the southeast (covered on the way back), are also found at lower altitudes (A&M 1065). The populations of Cerro Ayrampo have been subject to various taxonomic interpretations that have affected different genera and species within them. The first consideration is to decide which genus it belongs to, i.e. Rebutia K. Schumann, Sulcorebutia Backeberg or Weingartia Werdermann? Our position on a genus Weingartia as distinct from Rebutia (Anceschi & Magli 2010, 18) is summarized in the 2013 booklet (Anceschi & Magli 2013a, 88). Our position is confirmed by Nyffeler & Eggli (2010), who in turn distinguished Weingartia (including Cintia Knize & Riha and Sulcorebutia) from Rebutia on the basis of the latest molecular research (Lendel & al. 2006; Ritz et al. 2007; Lendel et al. umpubl. data; Nyffeler & al. umpubl. data). We recall that in the latest edition of Das Grosse Kakteen-Lexicon (Anderson 2011), Eggli reproposes the idea of Cintia, Rebutia,

Sulcorebutia and Weingartia as separate genera. On the contrary, in the 2nd edition of the NCL atlas, Hunt (2013, xììì) nothing changed compared to the previous edition (2006), i.e. keeping Cintia, Sulcorebutia and Weingartia included in Rebutia. The author concludes by quoting the analysis of Ritz et al. (2007), “... Sulcorebutia and Weingartia should be united into one genus, because neither molecular nor morphological data reveal a distinction between these genera”. Partially in disagreement with the judgment of these latter authors, we believe that Sulcorebutia and Weingartia have very little in common at the morphological level, even if the results of their molecular analysis leave no room to different phylogenetic interpretations. In fact, as can be seen from the cladograms (ibidem, 1324, 1326), Cintia, Sulcorebutia and Weingartia form a single well-supported monophyletic clade (in Bayesian 1.00, posterior probabilities ≥ 0.80; ibidem, 1326), distinct from Rebutia, equally well supported (in Bayesian 1.00, posterior probabilities ≥ 0.80; ibidem). Summarizing, based on the evidence, according to Nyffeler & Eggli 2010 we include Sulcorebutia in Weingartia, distinguishing it from Rebutia. Weingartia is therefore the genus name for these populations, but what is the name for the species? Following a brief history of the taxon’s interpretations at a specific level, involving the epithets pulchra, canigueralli and rauschii.

a) In Backeberg (1977, 469, 472), the three taxa are part of Sulcorebutia, and kept separate (S. caniguerallii, S. pulchra, S. rauschii).

b) In Anderson (2001, 601-602), the three taxa are part of Rebutia, namely Rebutia caniguerallii Cárdenas, which is divided into three ssp., among these  ssp. pulchra, while S. rauschii and Weingartia rauschii (Gerhart Frank) F. H. Brandt are considered synonyms of R. caniguerallii.

c) In Hunt et al. (2006, text: 246, 250, 315) the three taxa are part of Rebutia, R. caniguerallii and Rebutia pulchra Cárdenas as separate species, S. rauschii -W. rauschii, as synonyms of R. pulchra.

d) In Anderson & Eggli (2011, 609-610, 612), the three taxa are part of Sulcorebutia, Sulcorebutia caniguerallii (Cárdenas) Buining & Donald and Sulcorebutia pulchra (Cárdenas) Donald as distinct species, R. rauschii-S. rauschii-W. rauschii, as synonyms of S. caniguerallii.

e) In Hunt (2013), nothing has changed compared to 2006.

Based on a comparison of the morphological characters between the above-mentioned literature and our field surveys (see A&M numbers), the main distinction between S. rauschii = W. rauschii (we have already opted for Weingartia at the generic level), and the other two taxa, i.e. Weingartia caniguerallii (Cárdenas) F. H. Brandt and Weingartia pulchra (Cárdenas) F. H.  Brandt, is that the specimens representing the latter always show non-dark colored spines, i.e. different from black, that is dark brown or dark red; in the  examined documents:

W.  pulchra (Hunt et al. 2006, atlas: 260, 260.4 (as R. pulchra) col. brown variegated yellow

W.  pulchra (Hunt et al. 2006, atlas: 260, 260.5 (as R. pulchra) col. white

W.  pulchra (Anderson & Eggli 2011, 612 (as S. pulchra) col. reddish yellow

Only when the taxon photographed to represent W. caniguerallii (Anderson & Eggli 2011, 609 (as S. caniguerallii) or W. pulchra (Hunt et al. 2006, atlas: 260, 260.6 (as R. pulchra) is S. rauschii = W. rauschii, the specimens show dark spines. Furthermore, the average of the data contained in Backeberg's description of S. rauschii (1977, 472), is the one that best fits the data we collected in the Cerro Ayrampo populations. Finally, it is noteworthy that the description of R. pulchra in Hunt et al. (2006, text: 250), has substantially become that of S. rauschii of Backeberg (1977, 472), without anything remaining from the previous description of the first taxon (ibidem, as S. “pulchera”). Thus it seems that the new concept of R. pulchra has been "redesigned" on the characters of the well-known S. rauschii = W. rauschii. As for the reasons for the merging of S. rauschii into R. pulchra, in a note Hunt et al. (2006, text: 250) refers to Hunt (2006, CSI 21: 14), where, without other justifications, only a list of taxa to be subsumed in R. pulchra appears (i.e. R. caracarensis, S. crispata, S. frankiana, R. inflexiseta, and S. rauschii). For the reasons explained, with reference to the Weingartiapopulations of the Cerro Ayrampo, we prefer to strictly refer them to W. rauschii, keeping this taxon separate from W. caniguerallii and W. pulchra. (Quoted from Anceschi & Magli 2021, 85-87)