Mint family (Lamiaceae)
Perennial spreading via above-ground stolons. Stem erect rising 10-30 cm above the ground, weakly four-sided in cross-section and hairy. Basal leaves in rosettes, obovate, somewhat crinkled. Stem-leaves in opposite positions, sessile. Flowers blue-violet in colour, 6-16 in verticillasters, higher up forming a spike. 5-toothed calyx. Corolla 10-15 mm long; upper lip reduced, lower 3-lobed. Flowers Apr.-Jul.
Grows on fertile or semi-fertile mesic soils, in mixed/coniferous forests, oak woodlands and oak-lime-hornbeam forests. Also on meadows. Once used in wound disinfection.
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