Chimaphila japonica Seeds | Japanese Wintergreen
LATIN NAME: Chimaphila japonica
COMMON NAME: Japanese Wintergreen
Plant Profile
Japanese wintergreen is a small evergreen subshrub of cool, mossy forest floors, growing ten to twenty centimetres tall from a creeping rootstock. Its leaves are thick, glossy and dark green, arranged in a loose whorl near the top of the stem, with a pale stripe along the midrib. In summer it lifts one to three nodding white flowers on slender stalks, and these are followed by upright, round seed capsules that persist through winter and turn brown. The plant is semi-parasitic on the fungi in the soil, taking carbon from its mycorrhizal partners while still photosynthesising, which is why it grows only in undisturbed leaf litter and why transplanted plants almost always die. It is a plant of old forests, and its presence is a sign that the soil has not been disturbed.
Science & Biotechnology
Chimaphila, like its relatives in the wintergreen tribe of the heath family, has lost most of its chlorophyll in some tissues and depends on a partnership with ericoid mycorrhizal fungi that also connect to neighbouring trees. This mixotrophy, part photosynthesis and part fungal theft, has been studied with isotope labelling, and the results show that a substantial share of the plant’s carbon can come from fungi. The seed is dust-like, with almost no food reserve, and germination depends on infection by the right fungus within days, which makes propagation from seed unreliable and explains why the plant is almost always propagated by division. The genus has a disjunct distribution across the northern hemisphere, and the Japanese and North American populations have been separated for millions of years.
Uses & Benefits
The plant is grown by specialists as a curiosity for a shaded rock garden or a peat bed, where its glossy winter leaves and summer flowers reward close inspection. It has a history in North American and Asian folk medicine as a diuretic and a tonic, and it appears in old herbals under the name pipsissewa, but the medicinal use has largely been abandoned. Its greatest value in the garden is as an indicator: if it thrives, the soil is acid, humus-rich, undisturbed and consistently moist, which is exactly what rhododendrons, trilliums and woodland orchids need. It is not a plant for a beginner, and wild-collected plants should be refused, since they rarely survive the move.
Growing from Seed
Seed is difficult and should be surface-sown on a mix of sieved peat, leaf mould and sand, then watered with rainwater and kept in a closed container in deep shade at fifteen to eighteen degrees. Germination is erratic and depends on the presence of a compatible fungus, which is why most growers fail. The reliable method is division in early spring, taking a rooted piece of the creeping stock with several leaves and potting it in pure leaf mould from its own site. Keep it in a shaded frame for a year, then plant out into acid humus under conifers. Never let it dry out, and never apply fertilizer.
Our Take
A forest-floor plant that lives partly on fungi and refuses to be hurried. Buy it only as propagated stock, never dug.
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