Rust Fungi with Caeoma-Like Sori on Conifers

SUMMARY

Comparative morphological study of spermogonia and aecia suggests approaches to solving problems of unknown life cycles of caeomatoid fungi that parasitize conifers. Aecia of Melampsora, although called caeomatoid, in fact have peridia; Peridermium cedri has the same kind of peridium and is probably a Melampsora alternating to Salicaceae. Caeoma deformans and Uredo apacheca on Cupressaceae appear related to Gymnosporangium even though no caeomata are known for that genus. Caeoma espinosae on Cupressaceae and Caeoma torreyae on Taxaceae probably belong to undescribed primitive genera of Uredinales that are not derived from the supposedly ancestral Pucciniastreae, but which show characteristics of both Gymnosporangium and Milesina.