In 2005, Martin Lowry, before publishing it in the New Cactus Lexicon (Hunt et al. 2006), identified several new combinations of Echinopsis Zuccarini in Cactaceae Systematics Initiatives (2005, 19: 11-12). Among these, page 12 lists Echinopsis bridgesii ssp. vallegrandensis (Cárdenas) Lowry, from which the following is the full text:

14049 E. bridgesii ssp. vallegrandensis (Cárdenas) Lowry comb. et stat. nov. B: 00615 E. vallegrandensis Cárdenas, Cactus (Paris) 14 (64): 163-164 (1959). T: Bolivia, Santa Cruz, Florida, between Mataral and Vallegrande, 2700 m, Apr 1957, Cárdenas 5501 (CARD, US). Distinguished from ssp. bridgesii by its applanate habit, short, thicker, spines and more numerous ribs. 

Lowry points out that among the distinctive characters of the new taxon are its applanate habit and the higher number of ribs. If we compare the characters of Echinopsis bridgesii Salm-Dyck with those of the ssp. vallegrandensis in NCL ((Hunt et al. 2006, text: 92) we find that such distinctions do not stand up, rather they contrast with the data in the text. As we can see from the scheme, the elements of Lowry’s distinction does not exist. We also arrived at these conclusions by studying Echinopsis vallegrandensis Cárdenas in some of its distribution areas in Bolivia (Santa Cruz and Chuquisaca) in the zones between Mataral, San Isidro, Pulquina and the Rio Grande Valley. In fact, we did not find many differences compared to the populations of E. bridgesii that we saw in June 2007 in the surroundings of La Paz (Valle de La Luna). For example, the population of E. vallegrandensis found between Mataral and San Isidro on 20-Jul-2011 (A&M 670, photos 1-17), shows an average number of ribs of 12-14 (the same number of ribs as E. bridgesii) and individuals can reach 39 x 8 cm (h x ø) (photos 3-4). For these reasons, we believe that E. vallegrandensis should be included among the synonyms of E. bridgesii. (Quoted from: Anceschi & Magli 2013b, 45-46)

Anderson (2001, 263), considers Echinopsis ayopayana F. Ritter & Rausch synonymous with Echinopsis comarapana Cárdenas; the same position is maintained in Anderson & Eggli (2011, 226). Otherwise, Hunt et al. (2006), included E. comarapana among the synonyms of E. bridgesii ssp. vallegrandensis (Cárdenas) M. Lowry (ibidem, text: 94, 292), recognizing E. ayopayana among the accepted taxa, noting "Doubtfully distinct from E. bridgesii, though mature br become decumbent and > 1m long, a growth habit not seen in E. bridgesii.". Actually in different populations of the dominant and variable E. bridgesii we studied in habitat, individuals showing decumbent and elongated habits coexist with others, conforming to the standard dimensions of the species. See for example A&M 1107, Bolivia, Cochabamba, south-east of Cochabamba, La Angostura, photos 86-88 for semaphoronts (Hennig 1966, 6-7, 32-33, 63, 65-67) of the first type, and photos 93, 95, and 97 for those of the second. It is also worth noting as well as in areas close to the type locality of E. ayopayana (i.e. BO, Cochabamba, Ayopaya, between Indipendencia and Tiquirpaya), the populations show many individuals in the dimensional range of E. bridgesii (i.e. with non-decumbent stems, <1m long), see A&M 1129, Bolivia, Cochabamba, Ayopaya, below Yayani, 2090 m (photos 127-156). For the above reasons we add E. ayopayana to the synonymy of E. bridgesii. (Quoted from Anceschi & Magli 2021, 52)

It should be noted that before the publication of Lobivia krahn-juckeri Diers (Kakteen And. Sukk. 60 (8): 216 (215-223; figs. 1-19) (2009), in the Turuchipa area, Potosi, Bolivia, previous researchers (BB 1124.02 (2001), RH 350 (1989) identified this species with Echinopsis huotii (Cels) Lobouret, a taxon now referred by Hunt et al. (2006, text: 96) to Echinopsis bridgesii ssp. vallegrandensis (Cárdenas) M. Lowry (in cactusinhabitat.org both taxa are considered synonyms of Echinopsis bridgesii Salm-Dyck, see Anceschi & Magli 2013a, 45-46), or simply as E. bridgesii. Only after Prof. Diers publication in 2009, subsequent researchers (VOS 11-1077 (2011), LB 4055, LB 4057 (2011) began to search for it and identify it as Echinopsis krahn-juckeri nomen nudum, although some (MU 493.2 (2011), continued to identify it as E. huotii. Also Lowry & Winberg, in their article “Two to Turuchipa” (2013, 8: 44), regarding L. krahn-juckeri point out that “mature plants are almost indistinguishable from Echinopsis bridgesii ssp. vallegrandensis ", but that the protologue describes the taxon with short or long flower tubes and white, magenta, red or yellow flowers. In this regard, we are all aware of the fallability of the value of floral characters in defining taxa, following the recent molecular evidence (Ritz et al. 2007; Lendel et al. umpubl. data; Nyffeler et al. umpubl. data; Nyffeler & Eggli 2010; Schlumpberger & Renner 2012; Anceschi & Magli 2013a). Despite Lowry's change of opinion (2018, 22: 26-32) of now willing to recognize the rank of species of the Echinopsis from Turuchipa as Echinopsis krahn-juckeri (Diers) M. Lowry, on the basis of the surveys carried out by us in habitat (A&M 1097, A&M 1100 and A&M 1101), we are in line with its previous interpretation, and consider the populations of E. krahn-juckeri as one of the many manifestations of the dominant E. bridgesii. (Quoted from Anceschi & Magli 2021, 52-53)