Monocotyledonous.

Annual lanceolate herb. Stem creeping rooting, much branched, up to 1 m long, the lower part is glabrous, the upper part is short hairs.

Leaves lanceolate to ovate-lanceolate, 3-9 cm long, 1.5-2 cm wide.

Involucral bracts spathe-like, with 1.5-4 cm stalks, opposite the leaves, folded, unfolding to a cordate, apical short acute, basal cordate, 1.2-2.5 cm long, often hirsute at the margin.

Cymes, the lower branch with only 1 flower, with a peduncle 8 mm long, sterile; the upper branch with 3-4 flowers, shortly pedicellate, scarcely protruding from the spathe; pedicel only 3 mm long at anthesis, curved in fruit, not more than 6 mm long; sepals membranous, ca. 5 mm long, the inner 2 often close together or united.

Petals dark blue; inner 2 clawed, nearly 1 cm long.

Capsule ellipsoid, 5-7 mm long, 2-celled, 2 valves, with 4 seeds.

The seeds are 2-3 mm long, brownish yellow, truncated at one end, flat ventrally, with irregular fossae.

Produced in Yunnan, Sichuan, Gansu east of the north and south provinces and regions. Common, born in wetlands. It is also found in Vietnam, Korea, Japan, the Russian Far East, and North America.

Medicinal use, as a good medicine to reduce swelling and diuresis, clearing heat and detoxification, in addition to granuloma, pharyngitis, tonsillitis, cervical erosion, pit viper bites have a good therapeutic effect.

(From Chinese Botanical Records)