Spiraea betulifolia var. betulifolia(birchleaf spirea, "Marubashimotsuke")
Japanese name: マルバシモツケ（丸葉下野） Scientific name:Spiraea betulifolia var. betulifolia
[Overview]
A deciduous shrub 0.2–1 m tall, found on sunny rocky and gravelly ground and in Japanese stone pine communities from the subalpine to the alpine zone.
The branches are reddish brown and branch freely, forming a dense, rounded clump.
The leaves are alternate and simple, obovate to broadly ovate, 1.5–6 cm long and 1–4 cm wide, with the upper surface sunken and wrinkled along the veins.
The leaf margins are serrate.
Compound corymbs at the tips of the current year's branches bear many white, 5-petaled flowers 5–8 mm across, and the top of the inflorescence is somewhat convex.
Each flower has 20 stamens that protrude long.
The fruit is a follicle.
[Cultivation]
Propagate from seed or by cuttings.
It prefers a sunny, well-drained soil rich in humus.
Water thoroughly when the soil surface dries.
In spring and autumn, apply slow-release fertilizer placed on the soil.
Pests and diseases include powdery mildew and scale insects.
