Laminariocolax Tomentosoides on the Isle of Man

Abstract

Laminariocolax tomentosoides is a common epi-endophyte on the I.O.M. Though probably pseudoperennial as an endophyte it produces fertile external filaments only from September to June with a March maximum in size and numbers. It reproduces vegetatively by growing through its host's tissues and asexually by means of zoospores from plurilocular sporangia. In culture, zoospores give rise to fertile plants in 7 days and several generations can be produced in 4 weeks. The offspring bear only plurilocular sporangia. The chromosome number is apparently 16 and the life-history probably a postponed series of diplonts.Laminariocolax tomentosoides produces cysts which, in the past, have been mistakenly identified as unilocular sporangia and which are so similar to the ascocysts of Ascocyclus that this genus would seem to be based on a character of little value. Another description of unilocular sporangia in the species is tentatively attributed to infection by a fungus.