Iris sanguinea is conspecific with I. sibirica (Iridaceae) according to morphology and plastid DNA sequence data

Abstract

A taxonomic revision of Iris subser. Sibiricae is provided based on morphological and molecular analyses and the study of protologues and original material. Two to three species have been recognized in this subseries by botanists. To address the question of species delimitations and relationships within this group, we analyzed four non-coding regions of plastid DNA (trnS–trnG, trnL–trnF, rps4–trnSGGA, and psbA–trnH) for samples from 26 localities across the distribution ranges of two currently recognized species, I. sanguinea and I. sibirica. Variance analysis, based on nine characters, revealed no separation between taxa. Moreover, no morphological character could be used to define clear boundaries between taxa. Our results strongly support that I. subser. Sibiricae is monotypic and comprises only I. sibirica, instead of two or three species. Iris sibirica is morphologically variable and one of the most widespread Eurasian species of Iridaceae. Previously accepted taxa, I. sanguinea and I. typhifolia, are synonymised with I. sibirica and also two names, I. orientalis and I. sibirica var. haematophylla, which are typified here, are placed in the synonymy of I. sibirica. Information on the distribution of I. sibirica and the main features used to distinguish between I. sibirica and I. subser. Chrysographes species are provided.

Taxonomic Composition of Iris Subser. Chrysographes (Iridaceae) Inferred from Chloroplast DNA and Morphological Analyses

“…Sibiricae [10,11] known to horticulturists under the common name "Siberian irises" [12]. In a recent study [1], we confirmed that I. subser. Sibiricae includes only the highly variable I. sibirica (Figure 1b,c).…”

“…While revising the series Sibiricae (Diels) G.H.M.Lawr. of the section Limniris Tausch of the genus Iris L., we found that the taxonomy of this group remains unclear [1]. Iris ser.…”

“…Sequences of many cpDNA noncoding regions, including introns and intergenic spacers, have been used to assess interspecific relationships and suggested as molecular markers for species identification [31]. The regions trnS-trnG, trnL-trnF, rps4-trnS GGA , and psbA-trnH of cpDNA have proven to be useful as phylogenetic markers in the genus Iris [1,[32][33][34].…”

Seasonal arbuscular mycorrhiza colonization dynamic displays genotype-specific pattern in Iris sibirica L.

“…Many of the Iris sibirica found in cultivation today are tetraploids (Crișan et al, 2017), while interspecific hybrids are not uncommon in gardens, sometimes leading to confusion (Grey-Wilson, 1997;Kaššák, 2013). Traditionally, series Sibericae from section Limniris of the genus Iris, has been divided in two subseries, first one containing Siberian irises with 2n=28 that includes I. sibirica and I. sanguinea, as well a second one known as Sino-Siberian irises with 2n=40 (Boltenkov et al, 2020). For a long time, it has been known that Iris sibirica produces fertile hybrids with species from first subseries as well as unfertile hybrids with some species from the second one (Grey- Wilson, 1997).…”

“…For a long time, it has been known that Iris sibirica produces fertile hybrids with species from first subseries as well as unfertile hybrids with some species from the second one (Grey- Wilson, 1997). However, a recent study suggests that species I. sanguinea and I. typhifolia are in fact conspecific with I. sibirica explaining also the overlapping morphological traits (Boltenkov et al, 2020). The breeding trend for irises, including I. sibirica, has been the obtaining of cultivars with wide, ruffled tepals displaying high variation in colours and patterns (Crișan et al, 2017).…”