Euphorbia hypericifolia

Raab-Straube, Eckhard von & Raus, Thomas, 2025, Euro + Med-Checklist Notulae, 18, Willdenowia 55 (1), pp. 107-144 : 122-123

Euphorbia hypericifolia L. (≡ Chamaesyce hypericifolia (L.) Millsp.) – Fig. 12.

A Cm: Crimea: Yalta, Sovetskaya Square, 44°29'55"N, 34°10'09"E, 10 m, weed in flowerbed, 2 Sep 2023, Ryff (YALT); ibid., 8 Aug 2024, Ryff (YALT; photos [ Fig. 12]). – Euphorbia hypericifolia is native to tropical and subtropical regions of South and North America and known as an alien and often invasive plant from Africa, S and E Asia and the Pacific Islands ( Randall 2017; POWO 2024m). In the Euro+Med area it is recorded with increasing frequency from Spain, Italy, Greece and the Levant ( Sciandrello & al. 2016; GBIF 2024e). However, its definite introduction pattern is difficult to establish because the species is often confused with related taxa such as E. hyssopifolia L., E. indica Lam. and E. nutans Lag. In Crimea, E. hypericifolia first appeared in the summer of 2023 in the centre of Yalta, in the flowerbeds created during the reconstruction of Sovetskaya Square. The population is small: in 2023 and 2024 it included just some 10 individuals. Obviously, this species was introduced with imported planting material of ornamental plants, like another new record for the peninsula, Cardamine occulta Hornem. , which is also found here. This is the first record of E. hypericifolia for E Europe. From the closely related E. nutans , which was found in Crimea three years ago ( Kashirina & al. 2023), E. hypericifolia differs by a complete absence of pubescence (including on the leaves), conspicuous, deltate stipules and smaller fruits and seeds ( Sciandrello & al. 2016). In Yalta, E. hypericifolia grows together with another Euphorbia species recorded in recent years, E. prostrata Aiton ( Ryff 2019) . Unlike the latter species, which is already naturalized and actively spreading in Crimea, E. hypericifolia can be considered here only a casual alien so far. The addition of several new taxa of E. subg. Chamaesyce Raf. to the Crimean flora ( Yena 2006; Ryff 2019; Kashirina & al. 2023) in recent years indicates active expansion of this group to the peninsula.

L. E. Ryff