Leptodon Smith (Hedw.) Mohr in Ireland

Abstract

A new Irish locality is recorded for L. smithii, and the general features of the station are described. An account of the bryophyte succession on tree trunks in the area is given and the part played by L. smithii indicated. It is shown that gatherings from both Irish localities consisted entirely of male plants and the distribution and age of the antheridia on both specimens are recorded. It is suggested that rarity of sporophyte production in the British Isles is probably due to too great a spatial separation of male and female plants and not to the absence, or low production, of sex organs. It is also suggested that rarity of spores and impermanence of the habitat are the chief factors contributing to its rareness in climatically suitable areas of the British Isles. The known distribution of the plant in the British Isles is related to its European and world distribution, and it is shown that L. smithii may be expected in further Irish vice counties.

I have pleasure in acknowledging my thanks to Mr Wallace for the gift of a specimen of L. smithii from Knocklofty and for details of its habitat; to Mrs C. E. M. Shelswell-White for permission to enter and collect in the grounds of Bantry House, and to my colleague Dr J. G. Hawkes for confirming the identification of the two shrubs.