Cytological Problems in the Genus Crocus (Iridaceae): II. Crocus cancellatus Aggregate

Abstract

In her papers of 1957 and 1958 Feinbrun made the first reports of observations on wild-collected Crocus species and pointed out the need for more extensive studies in the genus using material from natural populations. In collaboration with Mr. Brian Mathew of the Herbarium at Kew, I am carrying out a cytotaxonomic study of the genus based on a large collection of known wild-source material. In the preliminary list of chromosome counts (Brighton, Mathew & Marchant, 1973) we demonstrated that Crocus is even more complex in nature than earlier workers had postulated from their studies of cultivated or unknown source material (Mather, 1932; Pathak, 1940; Karasawa, 1932, 1956). The wide range of chromosome numbers in the genus (2n = 6, 8, 1o, 12, I4, I6, I8, 20, 22, 23, 24, 26, 28, 30, 32, 34, 44, 48 and 64), together with the infra-specific variation found in some species and the considerable overlap of taxonomic characters in some groups, have demonstrated that even more intensive studies of natural populations must be carried out before conclusions may be made about the evolution and species relationships within this highly complex genus. The cytological work has, so far, been limited to chromosome number and karyotype analysis. Investigations of meiosis are in progress and it is hoped to extend this with studies of breeding systems. Where it has been impossible to classify satisfactorily a closely related group of species we have placed them collectively into aggregates (Brighton et al., I973). These complexes are being examined cytologically in a series of papers, the first of which (Brighton, 1976) dealt with the C. vernus aggregate. This paper considers the C. cancellatus aggregate which includes C. cancellatus Herb., C. mazziaricus Herb., C. cilicicus Kotschy ex Maw and C. damascenus Herb.