Article

The ex situ available genetic diversity of three extremely rare Spanish endemie plants now eonsidered extinet in Nature - Lysimachia minoricensis Rodr., Diplotaxis siettiana Maire and Helianthemum cirae Santos - has been studied on material preserved in a genebank using RAPDs markers. Either eonsidering the number of amplifieation products obtained, the nUffiber of polymorphic bands, the similarity among individuals or the total vari ance detected, the maximum diversity always corresponded to Diplotaxis siettiana while interrnediate values were obtained for Helianthemum cirae and the lowest for Lysimachia minoricensis. The correspondence of these results with the case histories of the three species is discussed.