Kin A. G., Mazzola M. B., Cenizo V. J., Seed germination and seedling growth of the geophytic Pterocactus tuberosus (Cactaceae), Journal of the Torrey Botanical Society, 2015, 142(4):283-291, doi: 10.3159/torrey-d-14-00056.1
Experiments on the effects of water potential, temperature and light on germination in Pterocactus tuberosus. A separate section compares the growth of young seedlings at three watering frequencies. The results describe the difference between germination conditions and drought tolerance after storage organs have formed.