Description of new species Tolypella iranica (Charophyceae, Characeae) and update of the species distribution range of T. mongolica

A new dioecious species of Tolypella having both male and female plants was discovered in a historical herbarium collection by Haussknecht from Iran. This species described here as T. iranica sp. nov. was identified based on morphological characteristics and molecular markers, including chloroplast (rbcL) and nuclear (ITS) DNA sequences. Additionally, a new genus record of Tolypella for Kazakhstan, T. mongolica, is reported and confirmed with scanning electron microscopy of oospores. Specimens from West Siberia earlier referred to T. hispanica were proved to be misidentified T. mongolica. These findings expanded the species distribution range to the European part of Kazakhstan and south of the West Siberian Plain making it one of the largest among dioecious species of Tolypella comparable with Mediterranean T. hispanica. The species distribution range of T. mongolica covers arid and semiarid inland areas of Eurasia. Typical surface ornamentation of T. mongolica allowing reliable species identification of oospores in brackish water could be helpful for paleoreconstructions in the central part of Eurasia. Non-overlapping distribution areas of all dioecious Tolypella species can be tentatively recognized as evidence of their allopatric speciation.