Herce M. F., Martorell C., Alonso-Fernandez C., Boullosa L. F. V. V., Meave J. A., Stem tilting in the inter-tropical cactus Echinocactus platyacanthus: an adaptive solution to the trade-off between radiation acquisition and temperature control, Plant Biology, 2014, 16(3):571-577, doi: 10.1111/plb.12085
Measurements of stem orientation, surface temperature and retained reproductive structures in an Echinocactus platyacanthus population in Metztitlán. A radiation model explains the seasonal benefits of a southward stem inclination in the intertropical part of Mexico.