The genus Veronicastrum belongs to the plantain family Plantaginaceae, and contains only two species, both of which enjoy humus-rich, moist conditions. V. villosulum is a native of Asia, and has arching stems, while V. virginicum, or culver’s root, originates from North America and has an erect habit. The latter has given rise to several widely grown cultivars, including ‘Lavendelturm’ (or ‘Lavender Towers’), which was selected by the renowned German plantsman Ernst Pagels. All have whorls of horizontal, lightly toothed leaves along the length of the stem, which can reach 2 m. This selection has racemes of tubular, pale lavender flowers with protruding stamens, and which are highly attractive to bees and butterflies.