A new species of Mattiastrum (Boraginaceae) from Turkey

Abstract

Some samples belonging to the family Boraginaceae that look interesting due to their erect stem, dense stem leaves, small flowers, and large nutlets have been collected around Tödürge Lake in the Zara district (Sivas, Turkey). As a result of the detailed investigations, it has been determined that these specimens are attributed to the genus Mattiastrum and they are similar to M. cappadocicum with their almost entire nutlets and their anthers attaching to the below part of the corolla fornices. While the new samples and their closely related species M. cappadocicum show similarities with their radially symmetrical, isopolar, 6-heterocolpate, and ectocingulate pollen grains, they differ in pollen size and shape, the length of colpus and pseudocolpus, and exine sculpturing. The Zara specimens are also different from M. cappadocicum by their dense imbricate stem leaves, oblong inflorescence, and completely glabrous, large (9.5–11 mm in diam.) nutlets with entire margins, and we therefore conclude that they belong to a new species. The description, photographs, general ecological preferences, conservation status in the light of current data, and also pollen morphological characteristics of the newly identified species are given.