A study on pollen grains ofCrocus cartwrightianus (Iridaceae)

Crocus cartwrightianus andC. cartwrightianus cv.albus pollen have been studied from structural and ultrastructural points of view and the germination assayed in vivo and in vitro.C. cartwrightianus pollen is regularly shaped and sized, has a low percentage of anomalous grains and has a high germination rate in vitro, whileC. cartwrightianus cv.albus is less regularly shaped with some variation in size and has a high percentage of anomalous grains and a low germination percentage in vitro. Ultrastructural observations have revealed, in the pollen of both the taxa, the presence of a thin elongated vegetative nucleus and a generative cell surrounded by a thin membrane. However,C. cartwrightianus pollen shows a thicker intine, andC. cartwrightianus cv.albus shows numerous pollen germination anomalies which are in common withC. sativus.