Salix discolor and Willow tree

Salix discolor noun - Small willow of eastern North America having greyish leaves and silky catkins that come before the leaves.

Willow tree and Salix discolor are semantically related. In some cases you can use "Willow tree" instead a noun phrase "Salix discolor".

Willow tree noun - Any of numerous deciduous trees and shrubs of the genus Salix.

Salix discolor and willow tree are semantically related. Sometimes you can replace phrase "Salix discolor" with "Willow tree", this phrases are similar.