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.
A tree shape with a bend pattern on the trunk. Regardless of the tree species it’s the most popular shape, and can be generally summarized in the outline of an isosceles triangle. If you place the branches on the outside of the trunk pattern, it will look good and it will be easier to maintain the tree shape.
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.
The Japanese devised the coded styles less than a hundred years ago. These styles make it possible to classify the trees according to the shape of their trunks, their branches, their roots. To know the styles is an obligatory base for amateurs. Though nowadays, without renouncing these styles, more importance is attached to the artistic values of movement, harmony and the coherence of the tree.
Bonsai classification by height:
Mame: up to 12cm / 5 inch
Shohin: from 12cm to 28cm / 5 – 11 inch
Chuhin: from 28cm to 60cm / 11 – 22 inch
Dai: from 60cm to 100cm / 22 – 40 inch
Bonsai classification by number of trunks on the same tree:
So-kan: 2 trunks
San-kan: 3 trunks
Go-kan: 5 trunks
Nana-kan: 7 trunks
Kyu-kan: 9 trunks