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Morphological and phylogenetic relationships of the worldwide Mediterranean lichen forming fungus, Parmelina quercina, have been studied. Specimens from western Europe, western North America and southern Australia were analysed using molecular data (nuITS rDNA, nuLSU rDNA and mtSSU rDNA) and selected morphological features (upper cortex maculae, scanning electron microscopy examination of the epicortex, ascospores and conidia shape and size, and amphithecial retrorse rhizines). The results conclusively reveal that: (1) there is not one single species but four separate species in the Mediterranean or sub Mediterranean areas of the world. Parmelina quercina and Parmelina carporrhizans (Euroasiatic species), Parmelina coleae sp. nov. (North America) and Parmelina elixia sp. nov. (Australia); (2) largely debated P. carporrhizans is not a synonym of P. quercina but supported as a valid species circumscribed to Macaronesic relict sites; (3) the geographical isolation of the Australian population is correlated with a large genetic distance; (4) morphological characters (ascospores and conidial variability and thallus epicortex) correlate with the phylogenetic hypothesis; (5) the new or revalidated species within Parmelina quercina are not cryptic species but morphologically recognizable taxa. © 2007 The Linnean Society of London, Biological Journal of the Linnean Society, 2007, 91, 455–467.

Karyological information on Cytisus species indicates at least two chromosome numbers for most of the taxa. This instability is a striking karyological feature of Cytisus . Chromosome numbers of taxa in Sect. Spartopsis and Sect. Alburnoides, both well represented in Morocco and the Iberian Peninsula, are presented here. We provide the first data on chromosome numbers for the Moroccan taxa C. grandiflorus subsp. barbarus , and subsp. haplophyllus ( n =23, 2 n =46), C. maurus (2 n =48), C. megalanthus ( n =23), C. arboreus subsp. arboreus , subsp. baeticus , and subsp. catalaunicus (2 n =50), C. valdesii ( n =23). New populations from the Iberian Peninsula have been counted C. grandiflorus subsp. grandiflorus (2 n =46), C. scoparius subsp. scoparius ( n =23), C. striatus subsp. eriocarpus ( n =23, 2 n =46), C. multiflorus ( n =23), C. oromediterraneus ( n =23, 24). Our data confirm the instability of the chromosome number in Cytisus . The presence of B chromosomes in C. valdesii and C. megalanthus , as well in other species, is discussed in relation to this instability and previous data. We suggest that instability of the chromosome number within a taxon, and even in the same population, may be related to the breakage of A chromosomes and the appearance of B chromosomes.

Karyological information about Iberian Genista species is limited because of their wide geographical distribution. It is a major factor in the understanding of a genus whose genetic evolution is mostly related to aneuploidy and euploidy. The chromosome numbers of the following taxa have been counted G. carpetana subsp. carpetana ( n =20), G. cinerascens ( n =12), G. micrantha ( n =18), G. mugronensis subsp. rigidissima ( n =18), G. ramosissima (2 n =48) and G. tinctoria ( n =24). The previously-assumed uniformity of chromosome 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 number, 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. tournefortii ( n =32). The data stress the necessity of obtaining chromosomal information from a number of plants of a taxon before its characteristic number is clear, and indicate that more chromosomal data will help the understanding of the cytological diversity within taxa in Genista .

The two subspecies of Ulex europaeus L. (subsp. europaeus and subsp. latebracteatus ) are easily differentiated by the shape and size of their bracteoles, and by their chromosome number. However, in the north-west of the Iberian Peninsula, the areas of both subspecies are not clearly delimited, the shape of the bracteoles is intermediate and the width is close to the diagnostic limit. Thus, allocation of some specimens to either subspecies is diffcult. Recently, a controversy has arisen concerning the intrapopulational uniformity of the chromosome number in U. europaeus from west France and north Spain, and the usefulness of ploidy level and chromosome number as clear-cut indicators of the two subspecies. Thus, the merits of recognizing the subspecies as independent are re-analysed here. Our results for north-west Spain show that the chromosome number is uniform and stable within populations and is clearly related to the morphological characters. Correlation and discriminant analyses show that bracteoles and stomata sizes are highly correlated and are good predictors of ploidy level. Furthermore, the results support the maintenance of two subspecies in U. europaeus , which can be delimited by a combination of morphological characters, chromosome number and geographical distribution.