Violets
Yakushima violet / Viola iwagawai / Yakushima sumire / ヤクシマスミレ
This small violet is endemic to the Ryukyu Islands. It is a perennial plant that grows about 5 centimeters high on damp forest floors and on wet rocks in mountain streams. The dark-green leaves are small, about 1 centimeter long, and are triangular with serrated edges. The peak flowering season is May and June, when small white petals appear with purple stripes on the lip. After flowering, it produces stems that branch off to form a new plant. It can often be seen along the walkway that leads up to the summit of Mt. Yuwandake.
Amami violet / Viola amamiana / Amami sumire / アマミスミレ
The rare Amami violet grows on moss-covered rocks in mountain streams, and is endemic to Amami-Oshima. Its leaves are small and shiny. The flowers, which bloom in April and May, are white—with yellowish green near the base, and reddish-purple stripes. The plant spreads through horizontal roots. It is classified as highly endangered.
Ryukyu tiny violet / Viola yedoensis Makino / Ryukyu ko-sumire / リュウキュウコスミレ
This is a perennial plant with wide distribution from southern Kyushu to Okinawa. It grows in sunlit areas to a height of 10 to 15 centimeters, with thick, triangular green leaves. The flowering season is long, lasting from November to April. The flowers are 1.5 to 2.5 centimeters in length, with petals that range from blue to reddish purple and, on rare occasions, white. It spreads through seeds.