Fig. 1-6. Bud variability in willows. Illustrations from Skvortsov (1999, 1955)
Alba-type of bud gradation
Caprea-type of bud gradation

Comparison of bud shape in S. caprea (3), S. cinerea (4), S. aurita (5), and S. starkeana (6). Buds in S. starkeana are similar to those in S. bebbiana