A Parasitic Plant Shaped like an Edo Footman
The Yakkoso (Mitrastemon yamamotoi) Habitat (ヤッコソウ発生地) is the habitat of yakkoso, Mitrastemon yamamotoi, a parasitic plant, at Yuda, Higashiichiki-cho, Hioki City, Kagoshima Prefecture, which in 1922 was designated a Natural Monument.
The Agency for Cultural Affairs lists it under the criterion for habitats of rare or endangered plants.
Hioki City says it appears at the foot of chinquapin trees on the hill behind Yuda Inari Shrine.
Ecology
The prefectural museum explains that yakkoso is an annual parasite of the Mitrastemonaceae, living on the roots of chinquapin (Castanopsis) trees, and sends up flowering stems in October and November.
The prefectural museum gives the stem height as about 7 centimetres; Hioki City gives 3 to 4 centimetres.
What to Look For
The name comes from the resemblance of the stem to a yakko, a footman of the Edo period, according to the prefectural museum; Hioki City likens it to a footman walking.
The small stems appear at the foot of the chinquapins only for a short time in autumn.
Visiting the Yakkoso (Mitrastemon yamamotoi) Habitat
No official visitor information could be found. The plant appears only in October and November.
As a Natural Monument, the plants must not be picked and the ground around the trees must not be trampled. Enquiries: Hioki City cultural section, 099-248-9432.
Q&A
- When was the Yakkoso Habitat designated?
- On 8 March 1922.
- What is yakkoso?
- An annual parasitic plant on the roots of chinquapin trees.
- Where does the name come from?
- Its stem resembles an Edo-period footman, or yakko.
- When can it be seen?
- In October and November.
- Where is the habitat?
- On the hill behind Yuda Inari Shrine, Higashiichiki, Hioki City.
Basic Information
| Name | Yakkoso (Mitrastemon yamamotoi) Habitat (ヤッコソウ発生地) |
|---|---|
| Location | Yuda, Higashiichiki-cho, Hioki City, Kagoshima Prefecture |
| Designation | Natural Monument |
| Year Designated | Designated 1922/3/8 (Taisho 11) |
| Quantity | Not recorded in the Agency for Cultural Affairs database |
| Dimensions | Flowering stem about 7 centimetres (prefectural museum) or 3 to 4 centimetres (Hioki City) |
| Owner | Not recorded in the Agency for Cultural Affairs database |
| Public Access | No official visitor information found |
References
- Agency for Cultural Affairs Database: Yakkoso Habitat (Japanese)
- https://kunishitei.bunka.go.jp/bsys/maindetails/401/2977
- Cultural Heritage Online: Yakkoso Habitat (Japanese)
- https://online.bunka.go.jp/heritages/detail/192242
- Kagoshima Prefectural Museum: Yakkoso (Japanese)
- https://www.pref.kagoshima.jp/bc05/hakubutsukan/tennen/kuni_tennen/04yakkoso.html
- Hioki City: Yakkoso Habitat (Japanese)
- https://www.city.hioki.kagoshima.jp/bunkazai/kurashi/kosodate-kyoiku/shakaikyoiku/bunkazai/higashiichiki/yakkoso.html
Last verified: 2026.09.28