As a variety of "O. basilicum", in Mrs. Burns lemon basil the calyx has five lobes, with a single-lobed posterior (upper) lip and a four-lobed anterior (bottom) lip. The posterior lip is decurrent on the tube. The throat of the calyx is open and bearded with a ring of hairs just below the mouth. The lateral lobes on the anterior lip are lanceolate and symmetrical. The tube of the corolla is dorsally gibbous at the midpoint at a point opposite of the appendage of the posterior stamen. Mrs. Burns lemon basil has four stamens, with an anterior pair near the corolla mouth and a posterior pair near the corolla base. The ovary is divided into four parts, which develop into single-seeded nutlets or mericarps. The nutlets produce copious mucilage when wet.