Japanese name: コスツス ドゥビウス Scientific name:Costus dubius
[Overview]
A perennial reaching 2 m in height.
The leaves are simple and alternate in a spiral, obovate-oblong, 10–30 cm long and 3–7 cm wide, with a wedge-shaped base and a long pointed tip.
The leaves are sparsely covered with soft hairs.
The leaf margins are entire.
The leaf stalks are short.
The flower stalk arises from the rhizome separately from the leafy stem and is short; at its tip it bears a pinecone-like spike covered with green bracts, and white flowers open 1–3 at a time from between the bracts.
The petals are trumpet-shaped, and one staminode is greatly developed into a petal-like lip, with a yellow throat.
The fruit is a capsule.
