“Reticulata irises”: a nomenclatural and taxonomic synopsis of the genera Alatavia and Iridodictyum (Iris subg. Hermodactyloides auct., Iridaceae)

Abstract

The “Reticulata irises” are dwarf irises highly appreciated in horticulture, which are characterised by their tuberiform bulbs, with a single fleshy inner tunic clothed mostly with reticulate or reticulate-hairy outer tunics, and basal leaves bifacial, angulose or finely sulcate in section. The aggregate is often accepted as a taxonomically compact group to which the name Iris subg. Hermodactyloides (Iris sect. Reticulatae) is often applied. It includes between 10–22 taxa (species and subspecies) occurring disjunctly from central Türkiye and the Transcaucasus throughout the Middle East to western China. Molecular work shows that Iris subg. Hermodactyloides, is polyphyletic as frequently delineated. Alternatively, analytic treatments accept two genera, Alatavia and Iridodictyum, exhibiting clear differences in morphology, biogeography, and phylogenetic connections. Recently, new field prospection across scarcely prospected vast territories led to the description of many new taxa in the “Reticulata irises.” In this context, an updated synopsis of the bulbous genera Alatavia (four species) and Iridodictyum (18 + 2 species) is reported. For each accepted taxon, main synonyms, type indication, chromosome numbers, distribution areas, and taxonomic or nomenclatural remarks are reported. Further, five new specific combinations are introduced, and also four neotypes, two lectotypes, two second-step lectotypes, and one epitype are designated.