New species Veronica × albachii Kosachev (Plantaginaceae) from Southern Siberia and Northern Mongolia

Summary . A new species Veronica × albachii (Plantaginaceae Juss.), discovered in the mountains of Southern Si-beria (Russia), as well as in Northern Mongolia, is described and illustrated in the article. The species is a hybrid taxon originating from the parent pair of V. incana L. and V. pinnata L. s. l.

Species of this subgenus often grow in completely different ecological conditions, sometimes extremely dry and rocky steppe (V.pinnata L., V. porphyriana Pavl., V. incana L.), sometimes mesic and swampy, along the banks of rivers, streams and lakes (V.longifolia L.).But in the conditions of variegated mosaic and complex altitudinal zonation in the mountains of Southern Siberia, different plant communities come into contact with each other.As a result, common occurrence of species with different ecological requirements becomes possible that opens the possibility of inter-species hybridization.
When processing herbarium materials in the ALTB Herbarium (Russia, Barnaul) from the genus Veronica from the Republic of Tuva (Russia), plants were discovered that differed from all species of Veronica we had seen.The plants had linearlanceolate pinnatifid leaves, and according to these characters they were similar to Veronica × sessiliflora Bunge.However, the pubescence of all parts of the plant with long sinuous simple hairs, and at the same time the complete absence of glandular hairs, clearly distinguished the studied plants from V. × sessiliflora.This prompted us to undertake a detailed morphological study of these plants.As a result of the study, it was found that we have a new species, which probably arose as a result of crossing V. incana (as indicated by the nature of the plant's pubescence) and V. pinnata (pinnatifid leaves -as was already shown in Kosachev et al., 2018Kosachev et al., , 2019)).Subsequently, we undertook a special search for this new species in nature in 2021.The plants were found in two localities in the Republic of Tuva, where they grew on dry mountain steppe slopes together with populations of V. incana and V. pinnata.This observation strengthened our assumption about the hybridogenic origin of the species.In addition, based on the studied herbarium materials in the ALTB Herbarium, three more localities were discovered in the Republics of Tuva, Khakassia and Mongolia (Fig. 1).
Below we provide a description of the new species, images of the type, general appearance and individual parts of the plant.Kosachev, nothosp.nov.(Fig. 2).

Fig. 4 .
Fig. 4. Pubescence of the stem and leaf petioles with long sinuous hairs in the lower third of the stem.

Fig. 5 .
Fig. 5. Leaves in the middle part of the stem.