Incised fumewort
Corydalis incisa

Family: Papaveraceae

What it is like

Corydalis incisa is a ANNUAL/BIENNIAL growing to 0.3 m (1ft). See above for USDA hardiness. It is hardy to UK zone 7. The species is hermaphrodite (has both male and female organs) and is pollinated by Bees. Suitable for: light (sandy) and medium (loamy) soils and prefers well-drained soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It can grow in semi-shade (light woodland). It prefers moist soil.

Height (m): 0.3

Where it is found

Thickets and bamboo forests in lowland and foothills all over Japan. Grows in marshes.

E. Asia - China, Japan, Korea.

Conservation Status: Not Listed.

Countries/locations it is found in

Native to China, Korea, Japan, and Taiwan. Introduced to Australia, USA, United Kingdom and is cultivated in the United Kingdom and possibly France, where seeds are sold online. This species does not appear to be commonly cultivated in Europe.

How it is used

Food

Rating: 1

Young plant - cooked in spring. Slightly deleterious.

Medicine

Rating: 1

The dried and powdered flowers are used in the treatment of rectal collapse. An aqueous decoction of the plant is used in the treatment of abscesses. Used in China and Japan in folk medicine to treat inflammation, headaches, skin diseases, and other ailments.

Miscellany: Various medicinal actions that need more clarification.

Other

Rating: 0

Miscellany: A rag-bag of items that are difficult to categorise.

How it is grown

Can be invasive outside its natural range. Corydalis incisa is an annual or biennial, spring-ephemeral herb. Seeds germinate in the spring and develop small rosettes, which wither during the summer. They emerge again as rosettes throughout the winter and produce compact flowering racemes the following spring. In its native range in Asia, C. incisa occurs along stream valleys, irrigation channels, and forest margins; in wastelands, roadsides, and forestlands; and on rock walls. In the United States, it grows in mesic and alluvial forest habitats. Under horticultural conditions, C. incisa prefers cooler exposures. The known distribution globally has Plant Hardiness Zones 6-10, areas with 20-100+ inches of annual precipitation, and the following Köppen-Geiger climate classes: humid subtropical, marine west coast, humid continental with warm summers, and humid continental with cool summers. There is no evidence that C. incisa occurs in Mediterranean climates. It is potentially suitable because the plants usually are dormant during the summer when conditions are driest in Mediterranean climates. The following notes are based on the general needs of the genus. Prefers a moist, well-drained rather light soil, thriving in semi-shade. Grows well in a woodland garden or peat bed. Plants seem to be immune to the predations of rabbits.

Propagating it: Seed - best sown as soon as it is ripe, the seed rapidly loses viability if it is allowed to become dry. Surface sow and keep moist, it usually germinates in 1 - 3 months at 15°c. Germinates in spring according to another report. Two months warm, then a cold stratification improves the germination of stored seed. Seedlings only produce one leaf in their first year of growth and are very prone to damping off. This species is a biennial and probably germinates more easily than the perennial species.

Best place to grow: Woodland Garden Dappled Shade; Shady Edge;

Habit: Annual/Biennial

Hardiness: 6-10

Growth:

Soil: Light (sandy), medium

Shade: Semi-shade

Moisture: Moist

Things to keep in mind

Although no specific mention has been seen for this species, there is a report that Corydalis species are potentially toxic in moderate doses.

C. incisa exhibits a strong ability to escape and spread. It is self-compatible with a high reproductive capacity. C. incisa is an emerging invader that poses a threat for some natural, production, and anthropogenic systems in the United States. Given that this species has only recently become invasive, there is little detailed information on its impacts. In New York, USA, dense populations of C. incisa dominate the understory, displacing native species and increasing the density of the herbaceous community. US Homeowners have been struggling to get rid of established plants through hand-pulling and the use of a flame-torch. Remove the tuber. Do NOT compost. DO NOT allow to flower as the seed is set quickly and disperses widely.

Its other names

Local names

Incised fumewort, Purple Keman, Murasa-kike-man (Japanese).

Synonyms

Fumaria incisa Thunb. (NGRP, 2017), Capnoides incisa Kuntze (The Plant List, 2017). The Plant List (2017) lists additional synonyms at the infraspecific level.