[Zimmerman A. D., Parfitt B. D., Thelocactus, Flora of North America North of Mexico, Oxford University Press, 2003d, tom 4]
A description of the genus and North American taxa, with stem, areole, spine and flower traits and their range of variation.
[Zimmerman A. D., Parfitt B. D., Thelocactus, Flora of North America North of Mexico, Oxford University Press, 2003d, tom 4]
A description of the genus and North American taxa, with stem, areole, spine and flower traits and their range of variation.