Abstract
Chromosome counts in somatic cells and unilocular sporangia of Pilayella littoralis f. rupincola, Striaria attenuata and Litosiphon pusilus from Sweden indicate apomeiosis in these taxa. This substantiates previous life history studies of P. littoralis f. rupincola and S. attenuata, both lacking sexual phase in this area, but does not agree with the suggestion that the likewise asexual L. pusillus would be meiotic. The chromosome numbers obtained were 24 in P. littoralis f. rupincola, about 30 in S. attenuata and about 20 in L. pusillus.