Diphasiastrum X Oellgaardii Stoor Et Al. (Lycopodiaceae, Lycopodiophyta), A Rare Lycopod Hybrid New To The Flora Of Turkey And Asia

In Europe, the genus Diphasiastrum comprises 3 species and 3 hybrids, with D. x oellgaardii (D. alpinum x tristachyum) being the rarest cross. To improve the distributional knowledge of these taxa, extensive studies were performed in a number of herbaria (BM, H, O, K, LE, LECB, MHA, NS, S, VLA; acronyms after Holmgren et al. 1990). In the herbarium of the Tsytsin Main Moscow Botanical Garden of Academy of Sciences in Russia (MHA), an interesting Diphasiastrum specimen collected in Turkey was discovered. It was labelled D. alpinum, but obviously is not this species. By thorough investigations of its morphology, we proved that it represents the hybrid D. x oellgaardii. This is the first record for Turkey, but also for Asia as a whole making it an important range extension. Furthermore, the herbarium studies revealed several unpublished finds of D. tristachyum in Turkey; these are also reported here. All known Turkish localities of D. x oellgaardii and its parent species are shown in a distribution map.