White flower (flower mid-May to early June)
It is a deciduous shrub of the Ericaceae family and is distributed throughout Unzen. They are especially common on the Jigoku Trail, and were designated as a national natural monument in 1928. From around mid-May when Miyama Kirishima flowers end, small cream-colored flowers like lily of the valley bloom in clusters.
In Unzen, most of them are shirodoudan, but in rare cases, pale pink flowers can be seen in some areas. Also, in autumn, the leaves turn red.
　Nejiki (flower late May to early June)
It is a member of the azalea that is about 4m high. Around June, many bell-shaped lily-of-the-valley-like flowers, about 1 cm long, are lined up in a row and put downward. It is characterized by its twisted trunk, and is also called the lacquered chopstick tree because its young branches are red in winter.
It is a poisonous plant like Japanese juniper and is not originally used in gardens, but it is often used mainly in gardens with miscellaneous trees because its trunk has a rustic feel and its astringent autumn leaves are preferred.
The leaves are particularly toxic (andromedotoxin, lyoniatoxin) and can cause vomiting and convulsions if eaten by humans.