Mint family (Lamiaceae)
A naked or sparsely hairy perennial with a prostrate stem 10-40 cm long. Leaves 1-4 cm long, opposite, roundish, reniform or cordate (kidney- or heart-shaped). Margins lobed and underside often purplish in colour. Flower stems erect, of square cross-section. 1-3 flowers present in leaf axils. Calyx 5-7 mm long, with five sepals. Corolla with two lips, 10-20 mm long, blue-violet in colour. Flowers Apr.-Jul.
Grows on fertile, mesic or moist soils, typically in somewhat shaded places. Encountered in riparian and oak-lime-hornbeam forests, and especially on their margins, as well as on meadows and in tall-herb vegetation. Leaves once used as flavouring and in soups, and species has medicinal uses.
Descriptions devised by the team at the Independent Department of Forest Botany, Warsaw University of Life Sciences, i.e. L. Witkowska-Żuk, K. Marciszewska, W. Ciurzycki, A. Obidziński and P. Zaniewski