Gymnocalycium marekiorum I. Milt spec. nov.
Milt, I. (2017): Gymnocalycium marekiorum Ivan Milt species nova. - Cactaceae etc. 27(4): p. 133-135
Holotyp: The material of the Holotype deposited in the Regional Muzeum in Olomouc with the number B 171.825. The type culture in the collection of Ivan Milt, the original collect VoS 49 (Volker Schädlich = VoS 03-49, near Villa Esperanza, southeast of the compressor station).
Etymology: Taxon named in the honour of Mr. Marek Milt from Haňkovice, Mr. Miroslav Marek from Litovel and Mr. Marek Grepl from Lutín - very famous gymno-grower, all Czech Republic.

Gymnocalycium gertii subsp. evelyniae Neuhuber et Gapon subsp. nov.
Neuhuber, G. & Gapon, V. (2017): A new subspecies of Gymnocalycium gertii Gapon et Schelkunova. - Cactus-Club 2017 (1): p. 23-29
Abstract: Western foothills of the Sierra de Comechingones in the Argentinean Province of Córdoba is a very interesting region for all gymnocalycium enthusiasts. Russian expedition-2011 found a new population of plants from the subgenus Gymnocalycium on the border of Córdoba and San Luis provinces, near Piedra Blanca. At first glance these gymnocalyciums look like dishevelled G. parvulum or fattened G. papschii, but the authors attributed them to the species of G. gertii. Certain morphological differences of a new find give reason to describe plants from the new population as a subspecies – Gymnocalycium gertii subspec. evelyniae Neuhuber et Gapon.
Typus: Argentina, border of Provinces of Córdoba and San Luis, Sierra de Comechingones, near Piedra Blanca, 1015 m above sea level, collected by V. Gapon VG11-1170, 27 of December 2011. Holotypus: WU Inventar Nr. 3912, plant in liquore alcoholico (VG11-1170/5074). Paratypus: WU Inventar Nr. 3501, dry plant (VG11-1170).
Diagnosis: Differs from G. gertii subspec. gertii Gapon et Schelkunova by larger flattened, not elongated stem, rather fewer ribs, fewer spines, larger flowers and ovary, fruits are more round.
Etymology: The new subspecies is named in honour of Evelyn Durst from Italy, an excellent photographer and popularizer of cacti and other succulents (Fig. 20, see p. 27), who also visited Argentina for field researches some years ago.

Gymnocalycium alenae Kulhánek species nova
Kulhánek, Tomáš (2017): Gymnocalycium alenae Kulhánek, a new species from the northern part of province Córdoba. - Schütziana 8(2): p. 24-38.
Abstract: A new taxon of the genus Gymnocalycium, subgenus Gymnocalycium (Cactaceae) was investigated in the northern part of the province Córdoba, Argentina and evaluated as a new species of possibly hybridogenous origin, partly related to the G. taningaense Piltz species group. A detailed plant description with differential diagnosis is provided. Information about ecology and possible relationships with other related taxa are given.
Typus: Argentina, prov. Córdoba: Sobremonte, Estancia La Quinta, in pure pasture with Acacia caven Molina in sandy soil, NW of crossroads connecting RP 22 and its side road RP 18, 648 m above s.l., leg. T. Kulhánek Tom 09-502/1, January 2009, (Holotype: CORD; Isotype: WU-0093296).
Etymologie: The epithet of new species is dedicated to the author’s daughter Alena.

Gymnocalycium ponomarevae Gapon et Neuhuber spec. nov.
Gapon, V.; Neuhuber, G. (2017): Gynmocalycium ponomarevae Gapon et Neuhuber – A new species from the Sierra de Ancasti. - The Cactus Explorer 18: p. 44-53.
Abstract: Gymnocalycium ponomarevae Gapon et Neuhuber is described in this article as a new species. It differs from the G. baldianum (Spegazzini) Spegazzini by the red-pink colour of the flowers and its style position, it has more ribs, more spines, a larger receptacle and ovary. It grows at lower altitudes than G. baldianum. It differs from G. baldianum var. albiflorum Bercht by having more ribs and radial spines, flower colour and a smaller ovary. It grows west of Villa El Alto, Province Catamarca, Argentina, at altitudes of 1050–1250 m above sea level.
Typus: Argentina, Provincia Catamarca, prope Vilisman, 1157 m s.m., leg. V. Gapon VG10-988/4547, 04.02.2010. Holotypus: WU (Inventar Nr. 4028, planta in liquore alcoholico); Isotypus: WU (Inventar Nr. 4029, 4030, flos in liquore alcoholico).
Etymologie: The new species is named in honour of Natalia Ponomareva (Moscow) – member of the 2012–2016 Russian expeditions to Argentina, Uruguay, Brazil and Bolivia, the wife of the first author. [Fig.29].

Gymnocalycium spegazzinii var. recii Milt var. nov.
Milt, I. (2017): Gymnocalycium spegazzinii Britton & Rose var. recii Ivan Milt var. nov. - Cactaceae etc. 27 (2): 33-36.
Typus: holotypus deposited in herbarium OLM section Botany, No. B 171479, type culture under No. 960 in collection of cacti (owner Ivan Milt), plants from imported seeds collected at type locality (Quilmes, Argentina).
Etymology: Named in the honour of Mr. Ing. Michael Rec, the presidend of the Olomouc Cactus Club.Foundplace: Prov. Tucuman, near to Quilmes, Ruinas de Quilmes.It differs from the type of the sort by colour of the pericarpel, colour of the epidermis which is quite evident already since the seedling of the first year and by the pitchblack colour of the spines.