The pussy willow belongs to the willow family, Salicaceae.
Pussy willows can be a shrub or a small tree. Their typical habit is to grow long, straight twigs without side branches that are covered in soft, velvety flower buds called catkins in the very early Spring / late Winter before the leaves sprout. The catkins look and feel like little kitten paws.
Pussy Willow is the common name for several species of willow family. The scientific name for the most common pussy willow is Salix discolor. It has gray catkins and brown branches. It is hardy in Zones 4–8 and is native to the Eastern United States. Several other species of willow with silky catkins are also known as pussy willows.
Forcing:
If the cut branches are placed in water indoors, in late winter, once the buds are fat but while they are still tight, they will open in the vase.
Flower Arranging:
If they are left in water after the buds open they will continue to mature, with the male catkins developing yellow pollen and leaves will appear along the branch. This is not desirable if the branches are being used for a decorative arrangement. If the decorative element of the branches is to be preserved they should be removed from water and allowed to dry after the buds are fully open but before the pollen and leaves appear. If handled gently the branches will retain the catkins indefinitely.
Propagation:
On the other hand if propagation is desired, willow branches left in the water will develop roots and can be planted to grow new plants. In fact willows root very easily in general and will often form a new plant if a cut branch is simply stuck in the ground.
Willow Lore:
In addition to the bark of the (all) willows having the active ingredient found in aspirin (salicylic acid) a tonic called "willow water" contains hormones that induce the roots of stem cuttings from other plants to grow. Soaking young, green willow stems (of any type) in a covered jar of water will make "willow water".