Herbaceous periwinkle, Vinca herbacea Waldst. et Kit. 1799 (Apocynaceae), a new species of the Croatian flora

Populations of herbaceous periwinkle, Vinca herbacea Waldst. et Kit., were found on April 2007 on Bansko Hill (Baranja, Croatia), which lies on the south-western edge of the range of this Pontic-Pannonian species. Since V. herbacea was included neither in the handbooks for plant identification nor in the current Croatian Flora Database, a new key for the determination of Vinca L. species of Croatia is presented herein. The herbaceous periwinkle should be treated as a critically endangered (CR) species in Croatia, considering the low number of individuals and the small extent of its occurrence in extremely rare habitats at the margin of its distribution. New recordings of some very rare or "data deficient" (DD) taxa of Croatia are also presented here: Scorzonera hispanica L. and Inula germanica L.