G. viereckii -ISI-91-9, a few years later in spring bloom
Gymnocactus viereckii -ISI-91-9 ex L1159
Gymnocactus viereckii -L1159
Gymnocactus viereckii -L1159
Gymnocactus viereckii -L1159
Gymnocactus viereckii -L1159
See photo in original gallery.