It is closely related to Datura, belonging to the same nightshade family, solanaceae. Brugmansia blooms dangle like great trumpets or bells while Datura blooms stand erect.
Verbena officinalis, the common vervain or common verbena, is a perennial herb native to Europe. It grows up to a metre/yard high, with an upright habitus. The lobed leaves are toothed, the delicate spikes hold mauve flowers.