''Rostellularia procumbens'', commonly known as water willow (, , ,), is a small flowering plant native to the Indian subcontinent, Indochina,

China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...

, Peninsular Malaysia,

Sumatra Sumatra is one of the Sunda Islands of western Indonesia. It is the largest island that is fully within Indonesian territory, as well as the sixth-largest island in the world at 473,481 km2 (182,812 mi.2), not including adjacent i ...

, Java,

Sulawesi Sulawesi (), also known as Celebes (), is an island in Indonesia. One of the four Greater Sunda Islands, and the world's eleventh-largest island, it is situated east of Borneo, west of the Maluku Islands, and south of Mindanao and the Sulu Ar ...

, the Philippines,

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...

, and Korea. It is found in higher elevations, commonly in humid areas. The leaves' juice can be squeezed in the eyes in cases of ophthalmia.

References

Acanthaceae Flora of China Flora of the Indian subcontinent Flora of Indo-China Flora of Japan Flora of Java Flora of Korea Flora of Peninsular Malaysia Flora of the Philippines Flora of Sulawesi Flora of Sumatra Plants described in 1847 Taxa named by Carl Linnaeus {{Acanthaceae-stub