Soft and Fair Goes Far: Common dandelions and Japanese native dandelions in Yokohama

It’s strange this spring in Yokohama. Like some other places in the north, flowers are blooming almost at once. In March, fully bloomed magnolias and cherry blossoms jostled for human attention. Then, it seems to me all the other flowers have come almost 2 weeks earlier than previous years, displaying their colors in competition. Global warming … there also are strange things, I guess. One of the cases in point: dandelions.

A scenery in Niiharu Citizen Forest this April …
 though if there is no comment many people think it is in May.

It’s almost a cliché among Japanese nature lovers, lamenting “ferocious invasion of common dandelions (Taraxacum officinale) to our landscape.” National Institute of Environmental Studies designate them as “one of the 100 worst invasive species of Japan.” Since their first identification in 1904 for Hokkaido region, they’ve spread almost all over Japan taking over the territories of their Japanese cousins, so they say. Common dandelions can take root even along asphalted road around Tokyo Station, as long as they can find a fissure for their roots to reach soil beneath. Moreover, they have ability to procreate even by self-pollination for almost all year round in globally-warmed cities. Japanese version does not have such flexibility for survival. Normally, those dandelions found by us city folks in our concreted environment are Taraxacum officinale. Also, their strong ability to multiply creates hybrid with native dandelions. Some estimate currently 80% of dandelions we find in Japan is such “half-bloods.” Thus, here is the mourning among Japanese naturalists. But I recently heard and found the story not so simple for the clan of lion flowers.

This is Japanese version.
 To distinguish them from officinale, please keep on reading …

Many Japanese native dandelions found in Yokohama are Taraxacum platycarpum. The way to differentiate officinale and platycarpum is in involucral scale beneath the petals. Non-native officinale has the thing like

Could you see their curly scale below yellow petals? In contrast, Japanese-native platycarpum is not so curly, like

When the flowers came to burst in Yokohama’s forests this spring, first I found dandelions did not come early as for the previous years. Even along the asphalted car road in downtown, I had an impression they were slow to appear this year. Finally in April, they became common. I turned over the dandelion flowers I encounter to see if they were officinale. To my surprise it was difficult to find them in organic environment. The majority of dandelion flowers I found in forests and natural fields in Yokohama are platycarpum. The pure-blood officinale is minority. In contrast, when I did the same in downtown surrounded by buildings, the dandelions were officinale or hybrids at best, and they are small.

Taraxacum officinale,
small and often groveling over not-so-good ground

In Niiharu Citizen Forest,
we also have Taraxacum albidum
 commonly found in Kyushu Island.
 The reason Niiharu has it is,
 in the early 20^th century, a bride came to Niiharu from Kyushu
 bringing its seed to remember her ancestral village.
 Their petals are white.

I’ve learned self-pollination tend to create smaller offspring among plants family. I guess this happens for Taraxacum officinale. Such small size does not work well when rapidly germinate officinale to survive in high competition with the other species, such as for spring and summer in forests or natural fields. In contrast, platycarpum are larger than officinale these days in Yokohama. Yeah, they procreate only once in a year during spring, but the seeds are larger, and the plants sprouting from them are bigger too. Their size containing lots of nutrients allows the seeds to sleep until autumn without germination. It is the time in forest when the competition for sunshine is relatively weak. Baby platycarpum can grow steadily during winter with globally warmer climate in Yokohama’s Citizen Forests. Meanwhile, adults platycarpum intentionally wither their leaves during summer to sleep only as roots. When chilly climate comes, they spread their leaves in rosette to receive max sunshine in less competitive world. After storing enough energy to procreate through easy photosynthesis, they bear larger flower for seeds when the air is warm enough for pollinator insects to be active. i.e. Although foreign officinale can multiply in limited concrete jungle by self-pollination, native platycarpum has a strong strategy to continue in wider and natural Japanese environment. This is their flexibility. Wow.

Large fluff of Taraxacum platycarpum.
So beautiful when they receive rain shower in Yokohama’s forest …

Er … actually, the reason why I found such things about dandelions are not at all for scientific study but to rationalize my sweet teeth. So many people say “Those foreign invasion eats over native dandelions, blah-blah-blah.” So I made a project to pick up flowers of officinale and cook them for sweets. “Let’s protect our endogenous environment and biodiversity” kind of things, you know. (Oh, it was Earth Day yesterday …) When I entered the nature of Yokohama, I carefully turned over the flower before picking them. My policy was like “If it’s officinale, pick it. Otherwise, leave them in the field. We must protect our native plants!” To my surprise, with this principle, not much foraging was possible in Yokohama’s forest. I was a kind of panicked and turned eyes to the asphalted roadside leading to natural parks. Here they are, small officinale ... Next week, I post my recipe for dandelion “honey” and dandelion cookies made of Taraxacum officinale. Though, now I’m not sure if my cookies are contributing to the biodiversity of our city … At least, I’ve heard officinale is common spring vegetable in France. Really?

If you find a problem in the greenery of north-half of Yokohama, please make a contact with

Office for the Park Greeneries in the North
北部公園緑地事務所
Yokohama Municipal Government Creative Environment Policy Bureau
横浜市環境創造局
Phone: 045-311-2016

FAX: 045-316-8420