Erythronium japonicum Poit.
Erythronium dens-canis japonicum Baker
Common Name: Katakuri
Erythronium japonicum is a harbaceous perennial plant growing up to 20cm tall from an underground bulb that can be around 6cm long and 1cm wide[
The plant is harvested from the wild for use as a food. The bulb is used to make a starch that is a popular food in Japan.
Although no records of toxicity have been seen for this species, the following notes have been seen for another member of this genus and so some caution is advised.
Skin contact with the bulbs has been known to cause dermatitis in sensitive people[
E. Asia - Russian Fa East, northeast China, Japan, Korea.
Woods in lowland and low mountains of C. and N. Japan[
]. Moist places in forests, S Jilin and Liaoning provinces in hina[
Prefers slightly acid soil conditions but succeeds in chalky soils if these contain plenty of humus[
]. Requires semi-shade, preferably provided by trees or shrubs, and a well-drained soil[
]. Succeeds in almost any light soil, preferring one that is rich in humus[
Slugs love this plant and often eat out the leaves[
Flowers are produced in 3 - 4 years from seed[
Bulbs should be planted about 7cm deep[
According to some botanists, this species is no more than a variety of Erythronium dens-canis[
Bulb - raw or cooked. The source of a starch, called 'katakuri-ko' in Japan. It is used in dumplings, confectionery, as a thickener in soups etc[
]. It is preferred over other starches for use in sauces which must thicken but not gel upon cooling[
]. The bulb is about 1cm wide and up to 6cm long[
Leaves - fresh or dried[
Seed - best sown as soon as it is ripe in a shady position in a cold frame. Water lightly in summer, it should germinate in autumn or winter[
]. Stored seed requires a period of cold stratification[
]. Sow as early in spring as possible in a cold frame. Sow the seed thinly so that it will not be necessary to prick them out for their first year of growth. Give an occasional liquid feed to the seedlings to make sure that they do not become nutrient deficient. When the plants are dormant, pot up the small bulbs putting 2 - 3 bulbs in each pot. Grow them on in a shady position in the greenhouse for another 2 3 years and then plant them out into their permanent positions when they are dormant in late summer.
Division of the bulbs in the summer as the leaves die down[
]. Larger bulbs can be replanted immediately into their permanent positions, but it is best to pot up smaller bulbs and grow them on in a shady position in a greenhouse for a year before planting them out when dormant in late summer.