Arisaema angustatum ("Hosobatennansho")

Japanese name: ホソバテンナンショウ （細葉天南星）
Scientific name: Arisaema angustatum

[Overview]
A perennial up to 1 m tall, found in forests and at forest edges from low hills to mountains.
It has an oblate corm underground.
The sheathing leaves and the lower part of the petioles form a pseudostem, which has rather strongly reddish spots.
The pseudostem is much longer than the petioles.
There are 2 leaves, each with 9–17 leaflets arranged pedately (like a bird's foot).
The leaflets are lanceolate to narrowly elliptic with pointed tips, and the leaf axis develops between the leaflets.
The leaf margins are entire, but often finely toothed.
The inflorescence stalk is erect, as long as or slightly longer than the petioles at flowering, and bears a spadix at the tip.
The appendage at the tip of the inflorescence is pale green, club-shaped and stalked, thick at the base and narrowing toward the tip; it is erect or bends slightly forward in the upper part.
The spadix is enclosed in a spathe.
The spathe is green with white longitudinal stripes; the tube is cylindrical, and the limb is shorter than the tube, triangular-ovate to broadly ovate with a pointed tip, sometimes with a purplish margin.
The mouth margin of the spathe spreads like ears (a collar) and curves back.
The fruit is an ovoid berry that ripens red.
The plant is dioecious; young plants are male and change to female as they grow.

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