Momiji: Acer palmatum

There are many scenes only in Japan having the four seasons, for example, mountains. In spring, colorful flower the bloome, green leaves sprout and photosynthesize by sunlight in summer, then change of leaves in autumn. The state is colored leaves and that main species is called Momiji(Maple). Maple usually turns red and the leaves have deep notches. But, Maple which we know commonly is not name of species; it means color change of leaves. Generally, maple is tree of Hiroshima Pref.

There are a lot of species of maples in Aceraceae Acer and Acer palmatum which is main species of broad-leaves deciduous forest, but Acer oblongum subsp. itoanum is an only evergreen as an exception. Ginkgo and Fagus are other species which colored leaves, so the color is not red but also yellow or brown. Japanese maple (Acer palmatum) is the most popular in Japan which has a height of there are 15m, the diameter of the trunk is more than 80cm. When colored leaves, many

Japanese maple which was used as decoration use is now seen anywhere in all over Japan, but the kind grow naturally prefer a low mountain above the sea level around 1,000m from the level ground.

The tree which turns red; examine is maple grow wild in the mountainous district of Fukushima Pref, southward. The place of the district in a high latitude belong to the subarctic zone is not suitable for the growth of the deciduous broad-leaved tree, conifers hold mostly there.

Mechanism of color change is very unique. Each ingredient is different as a colored leaved. At first, leaves of color are Green in summer because has Chlorophyll A, become cold and shorten hours of sunlight, chlorophylls A is resolves and make special tissue in joint of leaves. Next, Glucose, sucrose, amino acid; made in leaves, stored in itself, that is why new coloring matter is made from their sugar with photosynthesis, and then adjust the matter and male red or yellow color. Finally the leaves fall on the ground. In that, red colors of colored leaves is cause that chlorophyll change to anthocyanin, red from green, and yellow is change to carotenoid. But leaves that keep the original color, for example, purple color. Form of tree is various in Acer palmatum. For example, Japanese maple and Acer palmatum are become tall tree, their petal are very small.

Japanede meple was draw on Japanese old picture scrolls and cards, so it shows they are familiar to Japanese people. And maples are some 300 species from various breeding in Edo century.