Kerria japonica ‘Pleniflora’

Kerria japonica 'Pleniflora'
Kerria japonica 'Pleniflora'

After having written most of the today’s entry, a rewrite was in order; to censor a quote from one of my favourite movies, “I’ve got information. New (expletive) has come to light!”. It seems like the series on plants of Japan is becoming more of a series on “plants of China and / or Japan influenced by the other country” after yesterday’s Camellia hybrid and today’s Kerria japonica ‘Pleniflora’. Before getting into the details, first of all today’s photographs are courtesy of Jane of Missouri, USA, aka Shotaku@Flickr (original photo 1 | original photo 2 | Botany Photo of the Day Flickr Pool). Dōmo arigatō, Shotaku.

When I first encountered Kerria japonica ‘Pleniflora’ some years ago, I couldn’t immediately tell what family it was a part of. The problem was the lack of flower characteristics due to the ‘Pleniflora’ — in this case, a “doubling” mutation where the stamens instead develop into petals and the plants are sterile (for a different kind of doubling mutation in the same family, see Rubus spectabilis ‘Olympic Double’. Now that I’ve mentioned Rubus is in the same family, I’ve given away that Kerria japonica ‘Pleniflora’ is a member of the Rosaceae.

Kerria is named after William Kerr, noted by Wikipedia as “the first Western professional full-time plant collector active in China” and the person who introduced Kerria into cultivation in Europe by sending Kerria japonica ‘Pleniflora’ to England in 1805. It twigged on me that Wikipedia’s account doesn’t mention Kerr taking a trip to Japan, so I started to question the name japonica, a specific epithet meaning “of Japan”.

Many, many references state that Kerria japonica, or “Japanese yellow rose” is native to China and Japan (and sometimes Korea). A little bit of digging first revealed that Thunberg, during a collecting trip to Japan in 1776, had first collected the species that was to be eventually named as Kerria japonica. However, the specimen was in poor or incomplete condition, so it was initially determined that the species belonged to a different genus (and family). When it was properly recognized as a new genus post-1805 thanks in part to the living material sent by Kerr, it was named after Kerr but retained the japonica specific epithet. What Thunberg (and Linnaeus, who published the original name) didn’t realize, though, was that Kerria japonica is apparently not native to Japan. It seems that it had been introduced as a garden ornamental from China! I haven’t had any luck tracking down the reference that asserts that Kerria japonica was never native to Japan, but a respected source makes the statement: Dr. Susan Hamilton of the University of Tennessee Gardens on Kerria; and Gerald Klingaman, retired horticultural extension agent at the University of Arkansas makes an allusion: Kerria japonica. If anyone knows of the reference, I’d be glad to add a link. Lesson? Always check your assumptions.

For gardening accounts and additional details of both the species Kerria japonica and its cultivated varieties, see Paghat’s page on Kerria japonica (with a small essay of its cultural importance in Japan!) or Tim Wood’s weblog entry on Kerria.

14 responses to “Kerria japonica ‘Pleniflora’”

  1. beverly Rogers

    Didn’t know it was so darn hard just to have a series on Japan! Thanks for your, as always, edifying information.
    I have this plant in my garden and although it tends to get a bit thicket-y and some despise in favor of the single version, I like its brightness in spring.

  2. Michael F

    Bean (Trees and Shrubs Hardy in the British Isles) states “This species is a native of China, and is only naturalised or cultivated in Japan”
    Worth getting hold of the single-flowered wild type, it is far more attractive than ‘Pleniflora’.

  3. Michael F

    Nice pic of the wild-type from Flickr:

  4. Angie G

    Dirr (Manual of Woody Landscape Plants)states…
    “Native Habitat – central and western China. Also occurs in the mountains of all the main Japanese islands”

  5. Gabrielle

    I love Kerria! Years ago when I worked at a local nursery, I asked about buying a little shrub which I admired. The owner asked which one, and when I said Kerria japonica, she laughed and said, “That’s practically a weed. Just take it.” I did, and though I had to leave it behind when I moved, I can still see it when I drive by that house, 20 or more years later.

  6. Nancy Palmer

    Those pics take me back to my old garden in Western New York. How I loved that plant after a long snowy winter!

  7. Eric in SF

    Here’s another wild form, taken at UC Berkeley Botanical Garden:

  8. wendy

    How moving is the story of the poor innkeeper’s daughter. Such a poor and most likely poorly educated girl, and how rich the symbolism of her response. Yet the Yamabuki Rose is in a sense not all that deficient. Failing to protect frogs from rain is surely not so reprehensible?

  9. Daniel Mosquin

    The Flora of China makes reference to the species occurring in Japan, but does not suggest whether it is native to Japan or not: Kerria japonica.
    USDA GRIN database, which is my go-to reference for nativity, lists it as being native to Japan: Kerria japonica. Actually, this is the reason I had to rewrite the entry, because after checking the distribution on GRIN, I didn’t feel the need to question the information.

  10. elizabeth a airhart

    thank you daniel -guess we all have memories of this plant
    the folk tales and paintings are interesting
    to read –
    april may- you will hopefully arrive for a breath takeing spring
    in the south land here in the usa tis glory time in the mountains
    and the valleys -come eary or by the 10th see the masters in augusta
    we will get to florida one of these days

  11. Barbara Lamb

    Interesting that the double is sterile, as we had one just “show up” here at the Zen Centre, seemingly out of nowhere. The length of bloom-time is one of its great attractions.
    Daniel, what movie were you quoting?

  12. Daniel Mosquin

    The Big Lebowski, but if you are interested in a profanity-free version of it, I suggest reading the first few scenes of Two Gentlemen of Lebowski.

  13. onlyheaven

    WOW this is gorgeous!

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