Informal upright style -The trunk is slightly bent and tapers toward the top. The top of the tree is straight above the base of the trunk. The branches are distributed asymmetrically. The lower branches must be placed at the outer side of the curves or bends.
In nature, trees are forced into all kinds of shapes under the influences of weather, wind and placement. Consequently, bonsai trees can have many shapes and sizes and, depending on their way of growing, they are grouped into various styles and shapes.
Maybe some shapes seem strange and unnatural, but they are all based on the way trees grow in nature. Each tree, however, has its own character and within a certain style there is still an enormous variety. Usually a bonsai tree is given its name according to its shape or the number of trunks it has.