AbstractAnnual growth rate and spore and capsule production was studied in 50 colonies of the epixylic hepatic,Ptilidium pulcherrimumin northern Sweden. Radial growth rate was independent of colony size but varied from year to year (mean value 5.2 mm year−1, range 3.5–6.3 mm year−1). Size at first sporophyte production was estimated to be 68 cm2and the age of first reproduction was estimated to be about 9 years. It was estimated that antheridia were formed the third year. No correlation between growth rates and reproduction was observed. Capsule density as well as capsule and spore production increased significantly with increased colony size. Differences between years in spore and capsule production (up to six-fold) were observed. The mean number of spores per capsule was 27 400 but significant differences between colonies (range from 18 000 to 44 000) were observed.