Comanthosphace japonica ("Tenninso")

Japanese name: テンニンソウ （天人草）
Scientific name: Comanthosphace japonica

[Overview]
A perennial found in moist places in forests, such as along mountain streams, often forming large colonies.
It has thick, creeping underground stems.
The stem grows 50–100 cm tall and has star-shaped hairs when young, but later becomes hairless.
Leaves are simple and opposite, oblong to broadly oblanceolate, 10–25 cm long and 3–9 cm wide.
The leaf margins are toothed.
The leaf stalk is short.
A cylindrical inflorescence 5–15 cm long emerges at the stem tip.
On the young inflorescence, broadly ovate bracts with tail-like pointed tips are arranged like scales.
The flowers are tubular, 8 mm long, two-lipped at the tip, and cream-colored.
There are 4 stamens, which protrude far out of the flower.
The fruit is a schizocarp.

[Cultivation]
Propagate from seed, by division, or from cuttings.
It prefers partial shade and well-drained, moisture-retentive soil.
When planted in the ground, it is best placed under deciduous trees.
For potted plants, from spring to autumn take care that the soil does not dry out, and water thoroughly when the soil surface dries; in winter, water so that the soil does not dry out completely.
For plants in the ground, rainfall is sufficient unless sunny weather continues.
In spring, apply slow-release fertilizer placed on the soil.
There are no particular pests or diseases.

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