Fagus japonica Fagus japonica Fagus japonica, known as the Japanese blue beech or in Japanese as inubuna ("dog buna") or kurobuna ("black buna"), is a deciduous tree of the beech family Fagaceae. It is native to Japan, where it is one of the main tree species in natural deciduous forests particularly on the Pacific side of the country. It reaches 25 metres in height. The growth habit is often multi-trunked. Bark is smooth and grey. The simple leaves are arranged alternately along the branch. They are slightly pubescent and slightly glaucous beneath, with 10–14 pairs of lateral nerves. Fruiting peduncles are 3–4
Fagus sylvatica in the buds. In autumn, the tree builds the reserves that will sustain it into spring. Given good conditions, a bud can produce a shoot with up to ten or more leaves. The terminal bud emits a hormonal substance in the spring that halts the development of additional buds. This tendency, though very strong at the beginning of their existence, becomes weaker in older trees. It is only after the budding that root growth of the year begins. The first roots to appear are very thin (with a diameter of less than 0.5 mm). Later, after a wave of above