Hypericum androsaemum (sweet-amber, "Kobozuotogiri")

Japanese name: コボウズオトギリ （小坊主弟切）
Scientific name: Hypericum androsaemum

[Overview]
A deciduous or semi-evergreen shrub 60–90 cm tall.
It branches well from the base and forms a dense, rounded clump.
The branches have ridges.
The leaves are simple and opposite, broadly ovate to oblong-elliptic, 4–15 cm long, and give off a faint fragrance when crushed.
The leaf base is truncate to heart-shaped, often clasping the stem, and there is no leaf stalk.
The flowers are borne 1–11 per cyme at the branch tips; they are yellow, 5-petaled, about 1.5–2 cm across, and open star-shaped or cup-shaped.
The petals are ovate, 0.6–1.2 cm long, and equal to or slightly shorter than the sepals.
There are many stamens, not divided into bundles, and their length is 0.9–1 times that of the petals, about the same as or slightly shorter than the petals.
The sepals are oblong to broadly ovate, 0.6–1.5 cm long, with rounded tips and entire margins.
The sepals spread outward during flowering and curve backward during fruiting.
The fruit is a rounded, swollen capsule that changes color from red to purple to black as it ripens.
In types with large flowers and reddish leaves, the fruit often stays reddish brown (rust brown) rather than turning black.
It closely resembles Hypericum inodorum, and is distinguished mainly by the following: the petals are equal to or shorter than the sepals, the stamens are about the same length as the petals, and the sepals spread outward in the flowering period and curve backward in the fruiting period.

[Uses]
Branches in the fruiting stage are used as cut-flower material.

[Cultivation]
Propagate from seed, by cuttings, or by division.
It prefers sun to partial shade and fertile, well-ventilated soil that drains well and retains moisture, and dislikes strong dryness.
Summer direct sun and dryness can cause leaf scorch, so it is best to provide shade in summer.
If the site is too shady, flowering is poor.
For potted plants, water thoroughly when the soil surface dries; for plants in the ground, water in the morning or evening during dry periods in summer, and otherwise rainfall is sufficient.
Apply slow-release fertilizer placed on the soil in spring and autumn.
If pruning, do it in winter.
Pests and diseases include thrips, aphids, scale insects, powdery mildew and rust.

[Notes]
There has been confusion: a plant first sold as a cultivar of Kobozu-otogiri was later reclassified as a cultivar of Hypericum inodorum.

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