On the genus Asplenium in the Iberian Peninsula

Abstract

The Asplenium species recorded from the Iberian peninsula comprise diploids and tetraploids, and of the latter, both auto- and allotetraploids occur. Evidence from the meiotic pairing behaviour of the chromosomes in synthetic hybrids is adduced to show how the mode of origin and interrelationships of such species can be elucidated, and specific reference is made to Asplenium foresiense, A. majoricum, A. petrarchae and A. billotii. The suggested occurrence of autopolyploidy in Asplenium cuneifolium is also discussed. Evidence is presented which shows that in the British Isles and Corsica serpentine plants previously regarded as autotetraploid derivatives of A. cuneifolium are in fact allotetraploid and almost certainly just specialized serpentine forms of Asplenium adiantum-nigrum. It is suggested that such forms of A. adiantum-nigrum could occur also on serpentine rocks elsewhere in western Europe, for example, in Spain and France.