Thalictrum aquilegiifolium var. intermedium ("Karamatsuso")

Japanese name: カラマツソウ （唐松草）
Scientific name: Thalictrum aquilegiifolium var. intermedium

[Overview]
A perennial about 0.5–1.2 m tall, found in sunny grasslands and at woodland edges in the mountains.
The stem branches well in the upper part and is hairless.
There are basal leaves and stem leaves; the basal leaves have withered by the flowering period.
The stem leaves are alternate and 3–4 times ternately compound.
The leaflets are ovate to fan-shaped, shallowly 3-lobed at the tip.
Membranous stipules are attached at the base of the petiole and at the base of the leaflet stalks.
An umbel to compound umbel at the stem tip bears many flowers.
The flowers have no petals, and the petal-like sepals also fall early after flowering.
There are many club-shaped white stamens, forming a conspicuous sphere about 1 cm across.
The fruit is an elliptical achene with 3–4 narrow wings and a stalk, and hangs down.

[Cultivation]
Propagate from seed or by division.
It prefers fertile soil that is well drained and retains water well.
Give it sun from autumn to spring, and keep it cool in partial shade in summer.
Take care that it does not dry out; from spring to autumn, water thoroughly when the soil surface dries, and in winter avoid letting it become extremely dry.
Apply basal fertilizer, and also place slow-release fertilizer on the soil in spring and autumn, making sure no fertilizer remains in midsummer.
Pests and diseases include soft rot, powdery mildew, spider mites and aphids.

[Notes]
The name compares the shape of the flower to the leaves of the larch (karamatsu).

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