Viola obtusa (blunt violet, "Nioitachitsubosumire")

Japanese name: ニオイタチツボスミレ （匂立壷菫）
Scientific name: Viola obtusa

[Overview]
A perennial growing in hills and mountains, preferring bright, dry environments.
It is usually covered with fine hairs.
The aerial stems grow long after flowering, and some reach a height of about 30 cm at fruiting time.
The basal leaves and the stem leaves at flowering time are round-heart-shaped, 2–3 cm long, with low teeth on the leaf margin.
The stem leaves after flowering are narrowly triangular-ovate, 2.5–4 cm long, with low teeth on the leaf margin.
The stipules are deeply pinnately divided.
The flowers are borne at the tips of flower stalks rising upright from the leaf axils; they are dark purple to purplish red, 1.5–2 cm across, and the center of the lip petal is white with purple streaks.
The petals are rounded and overlap one another.
The flowers are fragrant.
Behind the flower extends a flat, broad spur 6–7 mm long.
The summer flowers are cleistogamous.
The fruit is a capsule that splits into 3 when ripe and scatters the seeds.

[Cultivation]
Propagate from seed, by stem cuttings, or by division.
It prefers partial shade and well-drained soil rich in humus.
It is easy to grow, but powdery mildew may occur.
Pests include aphids, spider mites, armyworms and the Indian fritillary butterfly (Tsumaguro-hyomon).

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