Sentence:  The character of trees may be studied to advantage ... in winter, when the forms of the <WSD>ramification</WSD> can be seen in the naked boughs ... 
Meaning of the word marked with <WSD> tags:  A branching-out, the act or result of developing branches; specifically the divergence of the stem and limbs of a plant into smaller ones, or of similar developments in blood vessels, anatomical structures etc.