Watercress (Nasturtium officinale) is a fast-growing perennial aquatic or semi-aquatic plant. The creeping stems are thick, hollow, up to 50-60 cm in length. Leaves are green, pinnately dissected, with wide petioles. The plant has white small flowers, collected in semi-umbrellas. The petals are white. The fruit is a short, with convex valves pod. It has oblong, flat seeds. The seeds are arranged in two rows. The blooming period is in May and August.