A rhizomatose perennial, with 4-angled, narrowly winged stems, up to 100 cm tall. Leaves 10 to 20 cm long, oblong to ovate, often with 1 to 4 pairs of lobes around the base, with crenate to toothed margin. Flowers in opposite to alternate many-flowered, dense cymes. Corolla bell-shaped, 5 to 9 mm long, greenish yellow with purple upper lip. Calyx 2 to 3 mm long, with rounded lobes which have a narrow papery, toothed margin. Fruit capsule ovoid, 4 to 6 mm long.
Local:Rare in Gibraltar.
Global:Found in western and south-western areas of the Iberian Peninsula.
Flowers from April to July
Found as a weed in cultivated plots. Grows in wet places