Asarum megacalyx ("Koshinokan'aoi")

Japanese name: コシノカンアオイ （越の寒葵）
Scientific name: Asarum megacalyx

[Overview]
An evergreen perennial growing in deciduous forests.
The stem creeps along the ground.
The leaves are simple and alternate, ovate-broadly elliptic to ovate-halberd-shaped, 9–12 cm long and 6–8 cm wide, with a heart-shaped base.
The upper surface of the leaf is dark green and sparsely hairy, with or without markings.
The petiole is up to 20 cm long and is usually dark purple.
The flowers are dark purple to pale purple and bloom sideways at ground level.
The flowers have no petals; the upper part of the calyx tube, about 1.5–2 cm long and 1.4–2.4 cm in diameter, splits into 3 petal-like lobes.
Inside the tube there are 9–15 lattice-like folds.
The calyx lobes are broadly ovate, 1.2 cm long and 1.4 cm wide, spreading flat, thick, with a smooth surface.

[Cultivation]
Propagate from seed, by division, or by root cuttings.
Sow seeds immediately after collecting them.
It prefers shade and soil that is well drained and retains moisture.
It dislikes dryness, so water thoroughly when the soil surface begins to dry.
In spring and autumn, apply slow-release fertilizer placed on the soil.
Pests and diseases include southern blight, soft rot, anthracnose, viral disease, slugs and armyworms.

[Notes]
It is a food plant of Gifu-cho larvae.
"Koshi" refers to Niigata (Echigo Province), where it was discovered.

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