Japanese Maple: Two Different Trees and Why It Turns Red
"Japanese maple" actually refers to two different trees under a similar name. Most often it means irohamomiji, Acer palmatum — the finely cut five-lobed maple of Japanese gardens; its name comes from the leaf, whose lobes were once counted off by the syllables of the old iroha alphabet: "i-ro-ha-ni-ho-he-to." Strictly botanically, however, "Japanese maple" is another species, Acer japonicum, which unlike irohamomiji also grows in Hokkaido.
A reader searching for "Japanese maple" usually has in mind the finely cut red leaf from a garden, but under that name reference books hide two different species. Let's sort out how they differ in range and where the name irohamomiji came from — and, along the way, why some maples turn red only in autumn while others hold a dark red color all season. Separately, we'll look at where these trees are admired in Japan, from the mountains of Kyoto to the gardens that took root in Europe back in the nineteenth century.
Japanese Maple and Palmate Maple Are Not the Same Tree
In Japanese forests grow 27 wild species of maple — out of roughly 130 species in the genus Acer worldwide. The most common species in Japan is イロハモミジ, Acer palmatum: a deciduous tree up to 15 meters tall with finely cut five- to seven-lobed leaves. This is the one usually called "Japanese maple." But strictly botanically, "Japanese maple" is another plant, Acer japonicum, and it reaches up into Hokkaido. Acer palmatum in the wild does not reach there at all: its range ends in the lowlands of Honshu south and west of Fukushima, also covering Shikoku, Kyushu, and the southern Korean Peninsula.
| Species | Japanese Name | How to Recognize It |
|---|---|---|
| Acer palmatum | イロハモミジ | 5–7 narrow lobes with double serration, tree up to 15 m; this is the one commonly called "Japanese maple" |
| Acer amoenum, including variety matsumurae | オオモミジ / ヤマモミジ | leaf larger, usually 7 lobes, serrations coarser and less often double |
| Acer japonicum | ハウチワカエデ | 9–11 lobes, flowers noticeably larger; botanically this is the true "Japanese maple," reaching Hokkaido |
| Acer mono | イタヤカエデ | leaf edge without teeth, turns yellow in autumn, not red |
How "Maple" as a Genus Differs from One Japanese Species
Maple, Acer, is a large genus: about 130 species worldwide, from North America to the Himalayas and Southeast Asia. In Japan there are noticeably fewer wild species, 27, but it is here that especially many garden forms have been bred — irohamomiji alone has more than 120. Confusing "maple" as a genus with "Japanese maple" as one specific species is a common mistake: almost any maple native to Japan is "Japanese" only geographically, and there are more than a dozen species there.
楓: How the Leaf Lobes Were Counted Off by the Iroha Syllables
楓 — значение: maple — онъёми: フウ — кунъёми: かえで — 13 штрих(ов). 楓 — "maple": on the left the radical 木 "tree," on the right the phonetic 風 "wind." In China the same character names a completely different tree — the sweetgum — and maple there is usually written with the character 槭; the current Japanese meaning of 楓 took shape within Japan itself.
| Japanese | Reading | Translation |
|---|---|---|
| 楓 | kaede · kaede | Maple |
| 葉 | ha · ha | Leaf |
| 木 | ki · ki | Tree |
| いろは | iroha · iroha | The first syllables of the old Japanese syllabary |
| 掌状 | shōjō · shōjō | Palmate — the leaf shape that also gave the maple its Latin name |
| イロハモミジ | irohamomiji · irohamomiji | The most widespread maple species in Japan |
Why the Leaf Lobes Were Counted Off by the Alphabet
The most common species in Japan has a leaf divided into five to seven narrow lobes with a toothed edge. The name イロハモミジ comes not from a resemblance to something but precisely from this number: the lobes were once counted off by the first syllables of the old Japanese iroha syllabary — "i-ro-ha-ni-ho-he-to." The Latin species name, Acer palmatum, says roughly the same thing in the language of botany. Palmatum means "palmate," that is, resembling a palm with spread fingers — the same word 掌状 used to describe this maple's leaf in Japanese.
Trace 楓 along the guides — the character for maple, whose Japanese usage differs from the Chinese.
Red Japanese Maple: One Scenario or Two
"Red Japanese maple" is not a separate species but two different coloring scenarios of the same tree. In the wild irohamomiji, the leaf is green all summer and turns red only in autumn, along with the general seasonal cooling. But in many garden forms bred specifically for color, the leaf emerges already dark red or almost burgundy in spring and holds that shade all summer, rather than switching to it only once in autumn.
Why the Leaf Changes Color
In summer the leaf is green from chlorophyll, which hides the other pigments beneath it. In autumn, when the nights grow cold, chlorophyll breaks down faster than it is replenished, and in the dying leaf cells anthocyanin begins to accumulate — the red pigment of the same class that colors cherries and grapes. In garden forms with permanently red leaves, this same pigment is already present in the young spring foliage, so the seasonal color change is barely noticeable.
Where These Maples Grow — from the Mountains of Kyoto to the Gardens of Europe
The greatest number of wild and garden irohamomiji grow in the mountainous area around Kyoto: Mount Takao with Jingo-ji Temple gave the species another name, takaokaede, "maple of Mount Takao." Besides the mountains, these maples are deliberately planted in temple courtyards, gardens, and parks across the country — as an ornamental tree, not just as part of the wild forest. The autumn admiration of such canopies in Japan is called momijigari.
Maples That Have Long Grown Beyond Japan
From the nineteenth century, garden forms of irohamomiji began to travel: Europeans who had been to Japan and China started bringing them to Europe. Since then the Japanese maple has been a constant resident of botanical gardens and private parks in Europe and North America, alongside local maple species.
FAQ
- What is a Japanese maple?
- The name refers to two similar trees at once. Most often it means irohamomiji, Acer palmatum — a low deciduous maple with a finely cut five- or seven-lobed leaf, the most widespread species of the genus Acer in Japanese gardens and forests. Strictly botanically, "Japanese maple" is another plant, Acer japonicum, with larger flowers and a leaf of 9–11 lobes.
- What kinds of Japanese maple are there?
- In Japanese forests grow 27 wild species of maple out of roughly 130 species in the genus Acer worldwide. The most noticeable are irohamomiji with its narrow finely cut leaf, oomomiji and yamamomiji with larger and coarsely toothed leaves, and hauchiwakaede with 9–11 lobes. Itayakaede stands apart: its leaf edge is smooth, without teeth, and in autumn it turns yellow, not red.
- Why does the Japanese maple have red leaves?
- In most forms the leaf is green all summer from chlorophyll, and in autumn, when the nights grow cold and chlorophyll breaks down faster than it is replenished, the red pigment anthocyanin accumulates in the dying cells. In some garden forms bred specifically for color, the same pigment is present in the leaf from spring onward, and the canopy stays dark red all season rather than turning red only once in autumn.
- How is "Japanese maple" written in Japanese?
- The most widespread species is written with the character 楓 ("maple") or the word イロハモミジ in kana; the Latin name is Acer palmatum. The character 楓 consists of the radical 木 "tree" and the phonetic 風; in China the same character names a completely different tree — the sweetgum — and maple there is usually written with the character 槭.
- Where does the Japanese maple grow?
- Irohamomiji in the wild grows in the lowlands of Honshu south and west of Fukushima, on Shikoku, Kyushu, and the southern Korean Peninsula, but it is absent from Hokkaido. The botanically distinct Japanese maple, Acer japonicum, however, reaches up into Hokkaido. The greatest number of these trees are planted and grow around Kyoto — Mount Takao even received a second name from the maple, takaokaede.
- When does the Japanese maple turn red?
- In wild forms, in autumn, along with the general cooling: the farther north and higher in the mountains, the earlier. In some garden forms with dark red leaves there is almost no seasonal color change — they hold that shade from spring until the leaves fall.
Sources
Updated: 2026-09-22