Karyological and taxonomic notes on Genista L. (Papilionoideae, Leguminosae) from the Iberian Peninsula

Karyological information about Iberian Genista species is limited because o f their wide geographical distribution. It is a major factor in the underst anding of a genus whose genetic evolution is mostly related to aneuploidy a nd euploidy. The chromosome numbers of the following taxa have been counted : G. carpetana subsp. carpetana (n = 20), G. cinerascens (n = 12), G. micra ntha (n=18), G. mugronensis subsp. rigidissima (n=18), G., ramosissima (2n= 48) and G. tinctoria (n = 24). The previously-assumed uniformity of chromos ome number (n=24) for all the subspecies of G. cinerea is supported here by data from subspp. murcica and speciosa. In G. florida, a new chromosome nu mber, n=23, has been found for both subspecies (florida and polygaliphylla) . A discussion of the discrepancies between these data and previous ones is included. A new level of ploidy has been found in G. tournefortii subsp. t ournefortii (n = 32). The data stress the necessity of obtaining chromosoma l information from a number of plants of a tau;on before its characteristic number is clear, and indicate that more chromosomal data will help the und erstanding of the cytological diversity within taxa in Genista. (C) 1988 Th e Linnean Society or London.