Warren S. D., Aguilera L. E., Baggett L. S., Zuñiga M., Floral orientation in Eulychnia acida, an arborescent cactus of the Atacama Desert, and implications for cacti globally, Ecosphere, 2017, 8(10):e01937, doi: 10.1002/ecs2.1937
The position of 300 buds, flowers and fruits on 20 Eulychnia acida plants from two sites in Chile. Circular analyses show a predominance on the northern side of plants and stems. The discussion compares this geometry with reproductive organ positions in other cacti and considers assimilate transport and flower warming. The physiological mechanisms remain interpretations of the observed arrangement.