Ariocarpus seed structures

Fig. 20. Pollen of Ariocarpus. A. Polar View x 850, B. Structure of the exine x 1700. C. Outline of colpa and arrangement of pila in A. agavoides x 1700. D-G. Patterning of pila in A. fissuratus, A. kotschoubeyanus, A. retusus, and A. trigonus respectively. x 1700.