In drawing any plant, the principle of its growth must be understood in order to grasp the character of its outer form. No view of the whole is obtained from botanical, analysis or the cfassification of small details, whatever wonders of nature these details disclose. In drawing a plant the most important thing is the first impression - what is seen at first glance - and the correct rendering of this characteristic appearance, whether it corresponds to a type-form or deviates individually from the type.
Individual deviations are more quickly understood if the typical growths have been closely studied. This, of course, is most easily done with the largest plant structures, trees, rather than with the small ones. The principles of growth learned from the large plants are easily transferred to smaller ones, be they grass, flower tendril, or single leaf or petal. Thus, the artist, unlike the botanist, is concerned first with the large, immediately obvious form.
If we transpose our concepts of human anatomy to plants, then in trees and bushes the trunk, branches, and twigs correspond to the skeleton, and the leaves and flowers to the soft parts. The longer one considers this comparison the more fruitful it seems; the tree in leaf, like the human body, shows the shape of its skeleton only in part, although the peculiarities of its growth, called in plants "habitus," all derive from it. However, the foliage can alter the aspect of a tree much less than the soft tissues can change the appearance of a human. No tree suddenly becomes fatter or thinner; in a fixed position with a virtually constant climate and nourishment it will grow in the same way year after year, either strongly or poorly.
Yet, as always, comparisons should cease when they become lame, and principles should not be made too rigid. The life of plants follows rules different from those that govern mobile creatures. Their soft parts are organs, not muscles; their "skeleton" consists of vessels which have grown more or less rigid.
These vessels naturally continue right into the organs, leaves and flowers, and they often repeat the same pattern of growth as the stem and its branches. The leaf simplifies this pattern to some extent and makes it an obvious ornament in a drawing. It is no wonder that leaves and flowers (which, in essence, are also made up of leaves) should have been so frequently used as subjects for decorative ornament.
The type of leaf used often characterizes a whole style of ornament: acanthus for the Corinthian, vine and ivy leaves for the Gothic, and the water lily with its long, wavy stem for Art Nouveau. These are only a few examples, all of which used mainly graphic forms, even though they were carried out in relief. Plant forms were, of course, also used in the round; the most impressive example is, perhaps, the columbine shape used in the Renaissance.
The branch formation of a plant can be seen in a simplified, two-dimensional form in the veining of its leaf. The skeleton of a leaf is very similar in design to a bare tree, or to flowers and grasses which are stripped of their green. These general types of growth formation should be understood by the artist before he studies individual forms.
Without this understanding two mistakes often occur: either both typical and individual shapes are bungled and what should be a tree looks like a birch broom standing upright decked out with cotton wool, or so much attention is given to the type-form each time that the characteristics of the particular plant being drawn are overlooked. In either case the result looks amateurish.