Echinopsis tominensis (Weingart) Anceschi & Magli is a new combination published in cactusinhabitat booklet. South America 2011-2013 (Anceschi & Magli 2013, 40). For the phylogenetic hypothesis adopted for the assimilation of Cleistocactus Lemaire in Echinopsis Zuccarini see booklet (ibid., 22-29).
(June 2013)

For years, molecular analysis revealed the close relationship between Echinopsis s.l. and the other genera within the tribe Trichocereeae, or subtribe Trichocereinae (Nyffeler 2002, 317, 319; Schlumpberger 2009; Lendel et al. 2006, unpubl. data in Nyffeler & Eggli 2010). Even more recent molecular analysis of Echinopsis (Schlumpberger & Renner 2012), clearly demonstrated that a cladistically correct interpretation of the molecular data, in the direction of a monophyletic genus Echinopsis, leads to the assimilation in Echinopsis s.l., as currently conceived (Anderson 2001; Hunt et al. 2006; Anderson & Eggli 2011), of Cleistocactus Lemaire, Denmoza Britton & Rose, Haageocereus Backeberg, Harrisia Britton, Oreocereus (A. Berger) Riccobono, Weberbauerocereus Backeberg and 10 other genera of the Trichocereeae/Trichocereinae.

We've dealt extensively with the subject, in the part devoted to the taxonomy in our last booklet (Anceschi & Magli 2013b, 22-29). 

Our position is summarized in “The new monophyletic macro-genus Echinopsis. No risk of paraphyly, and the most convincing hypothesis in phylogenetic terms” appeared on Cactaceae Systematics Initiatives N° 31, pages 24-27 (August 2013).

The PDF of the Postprint is available here (PDF 168KB).

(February 2015)

The surveys we conducted in habitat in 2014, in the Chuquisaca and Tarija Departments of Bolivia, have shown that there is no clear correspondence between the natural populations of Echinopsis micropetala (Ritter) Anceschi & Magli (A&M 981, A&M 995, A&M 1050), and Echinopsis tominensis (Weingart) Anceschi & Magli (A&M 1013, A&M 1018), with the descriptions and images of the two taxa reported by Hunt et al. (2006), (as Cleistocactus tominensis (Weingart) Backeberg and Cleistocactus tominensis ssp. micropetalus (F. Ritter) Mottram). They describe for C. tominensis (ibidem, text: 49) a taxon with more ribs, 18-22, <5 cm in diameter and more spines, 8-9, compared to ssp. micropetalus, with 16-18 ribs, 6-8 cm in diameter, and fewer spines, i.e. 1 central and 5-6 radial (ibidem). The descriptions show the first taxon with denser ribs on the stem vs. the second with more spaced ribs. The images representing the two taxa in question (ibidem, atlas: 207) and also unchanged  in the subsequent edition of the atlas (2013, 207), show specimens with characters exactly opposite to their relative descriptions. Assuming that there must be a relationship between what has been detected in the originally described habitats of the two taxa, and what has been described and represented in the lexicons, then for a correct definition of the species in question, we believe the two images have been reversed. We then consider the image with more ribs and more spines (Hunt et al. 2006, atlas: 207, fig. 207.2), to be E. tominensis and the one with less ribs and less spines (ibidem, fig. 207.3), to be E. micropetala. According to Lowry (2016, 34: 165), precisely because of the distinct characters shown in relation to ribs and spines, we prefer to consider the two taxa as separate species. (Quoted from Anceschi & Magli 2021, 59-60)