Sentence:  They were rolling southward on the International. The timber was huddling into little, dense green <WSD>motts</WSD> at rare distances before the inundation of the downright, vert prairies. This was the land of the ranches; the domain of the kings of the kine. 
Meaning of the word marked with <WSD> tags:  A copse or small grove of trees, especially live oak or elm. (from 19th c.)