Source: Wikimedia Commons
Japanese Cypripedium
AdvancedCypripedium japonicum
A Cypripedium with two large fan-shaped leaves held opposite each other, between which a large pouched flower faces sideways. The white lip is patterned purple-brown, and it forms large colonies on the floor of bamboo and cedar woods.
About
Kumagaiso (Cypripedium japonicum) is a perennial slipper orchid. Its Japanese name likens the inflated lip to the horo cloak worn on a samurai's back and links it to the warrior Kumagai Naozane, pairing it with the related atsumoriso named after Taira no Atsumori. It grows from south-western Hokkaido to Kyushu in Japan and in Korea and China, in forest on low mountains, especially bamboo groves and cedar plantations, where it forms large colonies. Plants reach about 40 cm and carry two large, fan-shaped leaves with finely toothed margins, held almost opposite. In spring (around May) a single flower about 9-10 cm across faces sideways on a stem rising between them. The sepals and petals are greenish, and the large pouched lip is white with purple-brown markings. The rhizome has long internodes and can exceed 1 m in total length. It is listed as Vulnerable on the Ministry of the Environment Red List and appears on many prefectural red lists, and some colonies are guarded by local groups against poaching. It can be grown in the ground where conditions suit, but its long rhizomes make pot culture difficult. The similar Taiwanese C. formosanum has short rhizomes and suits pots better. In Japan wildflower nurseries sell plants.
Source: Wikipedia (CC BY-SA 4.0)
Size of the Japanese Cypripedium
The Japanese Cypripedium grows to Up to about 40 cm tall; flowers 9-10 cm across.
Basic Info
Origin
Japan (SW Hokkaido to Kyushu), Korea and China
Lifespan
Perennial; spreads by long rhizomes
Size
Up to about 40 cm tall; flowers 9-10 cm across
Temperature
15〜30℃
Humidity
50〜70%
Watering & Fertilizer
Sparing, dilute liquid fertilizer in the growing season
Growing Tips
Light & Placement
It grows on the floor of bamboo and cedar woods; give bright shade or dappled light.
Watering
It likes moist, humus-rich soil; do not let it dry out in growth, but ensure good drainage to avoid waterlogging.
Temperature & Overwintering
It dies back and rests in winter; it tolerates winter cold but should be kept from summer heat and stagnant humidity.
Soil & Repotting
Its rhizomes run long, so it is hard to keep in pots and does best planted out where conditions suit, in humus-rich, well-drained soil.
Dormancy Care
After the top dies back in autumn it is dormant; do not let the planting site dry out completely.
Pests & Cautions
A Japanese native; choose nursery-propagated plants rather than wild-collected ones. Some prefectures restrict collecting wild plants by ordinance. It is listed as Vulnerable on the Ministry of the Environment Red List.
Japanese Cypripedium FAQ
QWhat is the growing difficulty level for Japanese Cypripedium?
Advanced. A variety suitable for advanced growers. Requires advanced cultivation techniques and specialized equipment, with careful environmental adjustments needed.
QHow large does Japanese Cypripedium get?
The mature size of Japanese Cypripedium is Up to about 40 cm tall; flowers 9-10 cm across. This may vary slightly depending on cultivation environment and individual differences.
QHow should I water and fertilize Japanese Cypripedium?
Japanese Cypripedium: watering & fertilizer — Sparing, dilute liquid fertilizer in the growing season. Aim for appropriate frequency and amount.
QWhat is the typical price for Japanese Cypripedium?
The price of Japanese Cypripedium varies significantly by variety, characteristics, size, and lineage. Please check GrowerDirect's price guide for the latest market information.
Last updated: September 23, 2026
References & Sources
Edited & verified by: GrowerDirect Editorial Team
The classifications, regulations, and growing data on this page are created and verified based on the primary information database below.
Taxonomy & Authority
Regulations & Conservation Status
The whole orchid family is listed in CITES Appendix II (checked on Species+). International trade requires permits such as export permits, but no registration is needed to buy, sell or transfer plants within Japan. It is listed as Vulnerable on the Ministry of the Environment Red List. It is native to Japan and is not designated as a Nationally Rare Species under the Act on Conservation of Endangered Species (checked against the Ministry of the Environment list). Some prefectures restrict collecting wild plants by ordinance, so choose nursery-propagated plants rather than wild-collected ones.
Sources: Species+ (CITES) / Ministry of the Environment, Japan: list of Nationally Rare Species
Regulations may change. Always verify the latest information with the relevant authorities.
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Find listings for this species
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