Phylogeny, geographic distribution, and new taxonomic circumscription of the Crocus reticulatus species group (Iridaceae)

Abstract

Recent phylogenetic analyses proved several infrageneric units within the genus Crocus to be para- or polyphyletic. In an attempt to arrive at a system of Crocus that closely reflects species relationships, we provide here phylogenetic, morphometric, geographic, and nomenclatorial data for the species of a narrower-defined, monophyletic Crocus series Reticulati. We sequenced the ETS and ITS regions of the nuclear ribosomal DNA in 9 Reticulati and 19 outgroup species. Three chloroplast loci (trnL-F, rps16-trnQ, matK-trnK) were sequenced in the newly defined series Reticulati species and 1 outgroup. Data were analyzed with Bayesian and parsimony algorithms. The phylogenies resulted in 2 clearly separated, geographically defined species groups within the series Reticulati. The southern one comprises only the taxa from Turkey, while the species of the second group are distributed from Italy in the west through the areas north of the Black Sea to the Caucasus in the east. To arrive at monophyletic species we describe here C. danubensis sp. nov., C. filis-maculatis sp. nov., and C. orphei sp. nov. as new species, and we define C. reticulatus s.s. to comprise only the populations in the area north and east of the Black Sea.