Pussy willow and Sallow

Pussy willow noun - Much-branched Old World willow having large catkins and relatively large broad leaves.

Sallow and pussy willow are semantically related. In some cases you can use "Sallow" instead a noun phrase "Pussy willow".

Sallow noun - Any of several Old World shrubby broad-leaved willows having large catkins; some are important sources for tanbark and charcoal.

Pussy willow and sallow are semantically related. Sometimes you can replace phrase "Pussy willow" with "Sallow", this terms are similar.