抄録
A cytological study of Cerastium arvense L. in North America has been carried out using plant material from most of the range of the species. Chromosome counts of 2n=36, 72 and 90 were obtained. The single population with 2n=90 is a hybrid. Counts of 2n=72 and 90 are new for C. arvense in North America. Meiosis was regular in all the plants in which it was studied except in the hybrid and in a few cells of C. arvense ssp. maximum from Cannon Beach, Oregon. The diploid and the tetraploid can be separated by several morphological features including leaf shape, length of stomata, diameter of pollen and length and breadth of seeds.
