Epimedium grandiflorum arrived in Europe, in Antwerp, with Philipp Franz von Siebold’s plant collection from Japan, in 1830 according to some reports. Actually, during his 8 years in Japan, Siebold sent three shipments with an unknown number of herbarium specimens to Leiden, Ghent, Brussels and Antwerp. The important thing is that among them there were 2 plants of Epimedium grandiflorum, one with white flowers, and one with pale-violet flowers. They were planted at the Ghent Botanical Garden. Unsurprisingly, the large spurred flowers received a lot of attention because the only species of Epimedium known at that time was E. alpinum, which has small flowers. The Japanese name of E. grandiflorum – ikariso, comes from: ‘ikari’ – anchor and ‘so’- plant, the four long curved spurs of the flowers suggesting the four-claw anchor used by Japanese fishermen.
Epimedium grandiflorum spread rapidly into cultivation. Currently, there are countless varieties of this species, and it has also contributed as a parent of some important hybrid groups such as E. x rubrum, E. x versicolor and E. x youngianum. It has three recognised forms today: f. grandiflorum, f. flavescens and f. violaceum.
Epimedium sempervirens, resembles very much E. grandiflorum with the exception of the evergreen leaves and of a more elongated rhizome. It is endemic to the western side of S. Honshu. E. sempervirens has crossed with E. diphyllum in the wild to produce the white flowered E. setosum. I already featured the sweet E. sempervirens ‘Candy Hearts’ in ‘Plant Valentines’, and now the answer, if someone was asking – yes, there is a variegated Epimedium, see illustrated E. sempervirens ‘Variegatum’.
Epimedium diphyllum is actually the first Epimedium that arrived in Europe from Japan, sent by Franz von Siebold to Leiden. From there it spread to other botanical gardens and nurseries in England. A small and dainty species, today is known more in cultivation through the garden hybrids that belong to E. x youngianum. The name E. x youngianum is used to include all the garden hybrids between E. diphyllum and E. grandiflorum. The numerous varieties that exist in cultivation exhibit usually intermediate characteristics between the parents. In the wild, the same combination of parents lead to a new species: E. trifoliatobinatum.
Besides these, there are many Japanese hybrids of unknown parentage. They can vary greatly in their flower shape, size and colour. Japanese Epimediums have the same requirements for cultivation as the Chinese ones, with the only difference that they prefer a slightly acidic substrate. Using a fertilizer for acid-loving plants would probably give better results, especially if the irrigation water is alkaline.
If you didn’t get ‘hooked’ yet on the Chinese Epimediums I’m sure now is the moment.
There are so many varieties on the market today and it is hard to choose only a few images to represent the whole range of Japanese Epimediums. The following gallery presents only a few from the many Epimediums that one can see at Lost Horizons Nursery (near Guelph in Ontario).
Non-plants related: David Mitchell’s book The Thousand Autumns of Jacob de Zoet, recreates with authenticity the atmosphere of the nineteenth century Japan, and the life on Dejima, an artificial island close to Nagasaki Harbor, where Siebold also lived during his stay in Japan around the same time period.