Oenothera albipercurva – evening-primrose species new TO the flora of Lithuania

Oenothera albipercurva Hudziok was reported for the first time in the Lithuanian flora. It is tenth Oenothera species noted in Lithuania. It was found in the association Cladonio-Pinetum nearby Merkinė town in the southern part of the country in 2005. According to the early stage of development (June), fully-flowering plants were very sparse. Oenothera albipercurva is of hybridogenous origin (O. biennis L. × O. ammophila Focke), discovered and reported by Renner in 1937 from Germany, currently distributed in Central and Eastern Europe. It resembles O. ammophila by its narrow leaves and divergent sepal tips, but can be easily distinguished mainly by its clearly larger flowers (petal length 15–26 mm instead of 12–18 mm) and red papillae on the underside of leaves. Some examples of significant mistakes found in the descriptions of this species in literature and main diagnostic characters are given.