2020
Gymnocalycium castellanosii var. spinosior Milt 2020
Milt, I. (2020): Gymnocalycium castellanosii Backbg. ex Piltz var. spinosior Milt var. nova. - Cactaceae etc. 30(2): p. 46-48. ill.
Holotype: Regional Museum of Olomouc (CZ), inventary number B172329, living plant in collection I. Milt under number 868.
Argentina, prov. La Rioja, environment of the place Illisca.
Gymnocalycium megalothelon subsp. brasiliense Prestlé 2020
Prestlé, K. H.; Till, H.; Amerhauser, H. (2020): Gymnocalycium hyptiacanthum in Uruguay und Rio Grande do Sul - Teil 2. - Gymnocalycium 33(1): p. 1345-1364.
Type: Brasil, Rio Grande do Sul, mountain ridge of Cachoeira do Sul and Capivarita; leg. K. H. Prestlé PR 400-A, February 15th 1983 (RB, holo).
Brasil, Rio Grande do Sul, basalt- and granite containing hilly and mountainous area south of Cachoeira do Sul and Capavarita.
Gymnocalycium netrelianum subsp. albidulum Prestlé 2020
Prestlé, K. H.; Till, H.; Amerhauser, H. (2020): Gymnocalycium hyptiacanthum in Uruguay und Rio Grande do Sul - Teil 2. - Gymnocalycium 33(1): p. 1345-1364.
Type: Uruguay, Departement Treinta Y Tres, Cuchilla de los Ladrones; leg. K. H. Prestlé PR 705-A, Februar 22th 1992 (MVM, holo).
Eastern central Uruguay, Departement Treinta Y Tres, stony grassland at Cuchilla de los Ladrones.
Gymnocalycium netrelianum subsp. blanquilloense Prestlé 2020
Prestlé, K. H.; Till, H.; Amerhauser, H. (2020): Gymnocalycium hyptiacanthum in Uruguay und Rio Grande do Sul - Teil 2. - Gymnocalycium 33(1): p. 1345-1364.
Type: Uruguay, Departement Durazno, ca. 22 km soutwest Blanquillo, 400 m s.m.; leg. K. H. Prestlé, PR 1047-A , October 8th 2000 (MVM, holo).
South-Uruguay, Departement Durazno, desolate sandy grassland 22 km southeast von Blanquillo, 400 m s.m.
Gymnocalycium netrelianum subsp. stramineum Prestlé 2020
Prestlé, K. H.; Till, H.; Amerhauser, H. (2020): Gymnocalycium hyptiacanthum in Uruguay und Rio Grande do Sul - Teil 2. - Gymnocalycium 33(1): p. 1345-1364.
Type: Uruguay, Deptement Paysandú, 400 m s.m.; leg. K. H. Prestlé, PR 1022-A (MVM, holo).
Western central area of Uruguay, Deptement Paysandú, 400 m s.m.
Gymnocalycium netrelianum subsp. tamborense Prestlé 2020
Prestlé, K. H.; Till, H.; Amerhauser, H. (2020): Gymnocalycium hyptiacanthum in Uruguay und Rio Grande do Sul - Teil 2. - Gymnocalycium 33(1): p. 1345-1364.
Type: Uruguay, Departement Tacuarembo, Sierra de Tambores, 370 m s.m.; HA 1536 from seeds, leg. H. Amerhauser (MVM, holo).
Central-Uruguay, Departement Tacuarembo, growing on gravel surface in the Sierra de Tambores, 370 m s.m.
Gymnocalycium pungens Fleischer ex Milt 2020
Milt, I. (2020): Gymnocalycium pungens Fleischer ex Milt spec. nova. - Cactaceae etc. 30(3): p. 98-99.
Gymnocalycium uruguayense subsp. aureiflorum Prestlé 2020
Prestlé, K. H.; Till, H.; Amerhauser, H. (2020): Gymnocalycium hyptiacanthum in Uruguay und Rio Grande do Sul - Teil 2. - Gymnocalycium 33(1): p. 1345-1364.
Type: Uruguay, Departement Artigas, south Blanquillo; leg. K. H. Prestlé PR 1047, October 8th 2000 (MVM, holo).
Uruguay, Departement Artigas, desolate sandy grassland, 22 km südlich von Blanquillo.
Gymnocalycium uruguayense subsp. bernabeense Prestlé 2020
Prestlé, K. H.; Till, H.; Amerhauser, H. (2020): Gymnocalycium hyptiacanthum in Uruguay und Rio Grande do Sul - Teil 2. - Gymnocalycium 33(1): p. 1345-1364.
Type: Uruguay, Departement Artigas, Cuxilha Yacare; leg. K. H. Prestlé PR 1026, February 16th 1998 (MVM, holo).
North-Uruguay, Departement Artigas, west of Artigas, stony pampa like pastures in the Cuxilha Yacare near Bernabé.
Gymnocalycium uruguayense subsp. rionegroense Prestlé 2020
Prestlé, K. H.; Till, H.; Amerhauser, H. (2020): Gymnocalycium hyptiacanthum in Uruguay und Rio Grande do Sul - Teil 2. - Gymnocalycium 33(1): p. 1345-1364.
Type: Uruguay, Departemen Durazno, near Blanquillo; leg. K. H. Prestlé PR 1047-C, October 8th 2000 (MVM, holo).
South-Uruguay, Departement Durazno, south of the Rio Negro dam in a sandy habitat wirh spare tussok-grass, 22 km south of Blanquillo.
Gymnocalycium uruguayense subsp. schlosserianum Prestlé 2020
Prestlé, K. H.; Till, H.; Amerhauser, H. (2020): Gymnocalycium hyptiacanthum in Uruguay und Rio Grande do Sul - Teil 2. - Gymnocalycium 33(1): p. 1345-1364.
Type: Uruguay, Departement Artigas, Ruta 4, Border to Rio Grande do Sul; leg. H. Amerhauser HA 1519, October 31th 1999 (MVM, holo).
Uruguay, Departement Artigas, at the border to Rio Grande do Sul, rural, stony habitat, Ruta 3 at km 5, east of Ruta 4.
Gymnocalycium uruguayense subsp. topadorum Prestlé 2020
Prestlé, K. H.; Till, H.; Amerhauser, H. (2020): Gymnocalycium hyptiacanthum in Uruguay und Rio Grande do Sul - Teil 2. - Gymnocalycium 33(1): p. 1345-1364.
Type: Uruguay, Departement Artigas, at Cuchilla Yacaré; leg. K. H. Prestlé PR 1025, Oktober 6th 2000 (MVM, holo).
North-Uruguay, Departement Artigas, stony grassland at Cuchilla Yacaré.
Gymnocalycium volskyi subsp. angulatum (Prestlé) V. Gapon, Chikin, Ponomareva, Protopopov & Schelkunova comb. nov. 2020
Gapon, V.; Ponomareva, N.; Schelkunova, N.; Protopopov, B.; Chikin, C. Zaitseva, L. (2020): Gymnocalyciums from Sierra de Aceguá. - Kaktus Klub (2): p. 20-31.
Basionym: Gymnocalycium denudatum (Link & Otto) Pfeiffer ex Mittler subsp. angulatum Prestlé - Gymnocalycium 17(2004)2: 573
Type: PR 780, Brazil, Rio Grande do Sul, Caverá (ICN).
Brazil, Rio Grande do Sul, low mountains Serra do Caverá (mean height 174 m) between Alegrete, Rosário do Sul and Santana do Livramento.
Gymnocalycium volskyi V. Gapon, Ponomareva, Protopopov, Schelkunova & Zaitseva 2020
Gapon, V.; Ponomareva, N.; Schelkunova, N.; Protopopov, B.; Chikin, C. Zaitseva, L. (2020): Gymnocalyciums from Sierra de Aceguá. - Kaktus Klub (2): p. 20-31.
Type: Uruguay, Cerro Largo, Sierra de Aceguá, 296 m s.m., leg. V. Gapon 12.11.2018, VG18-1684/7859-10. WU (Inventar Nr. 3648 - dry plant [holo.], Nr. 4120 - flower in liquore alcoholico [iso.]).
Uruguay, Department Cerro Largo, Sierra de Aceguá, 296 m a.s.l., mountain range Sierra de Aceguá right at the border with Brazil. Grows on open terrain as well as covered under the bushes.
Gymnocalycium x elatum Řepka 2020
Řepka, R. (2020): Gymnocalycium x elatum, eine neue Nothospecies von Arten zweier Subgenera. - Gymnocalycium 33(4): p. 1387-1400.
Holotype: 28. November 2016, leg. Radomír Řepka (RER 804), holotype in the Herbarium of the Faculdad de Ciencias Forestales, Universidad de Santiago del Estero, Argentina (No. 2098).
Argentina, Prov. Córdoba, Dept. Punilla, Capilla del Monte, rocky pastures with Acacia caven at the western margin of the town (El Zapato), 980 m a.s.l.