The willow is the onlytree which has dwarf forms, but as these form little spreading bushes rather than trees, they may be appropriately included in the present section. Like their larger fellows, they bear catkins, which are usually more conspicuous on the female plants. They enjoy a moist and leafy, though well drained, soil, and do not mind full sun. Although dwarf in stature, most of them require plenty of lateral space, as their branches spread sideways instead of upwards; say 1 sq. ft. for each plant. The following are the smallest.
S. apoda has bright green leaves and grey-green catkins in April. 1 in.
S. Arbuscula is of more upright habit than the others, and has glossy green leaves and yellow catkins. April and May. 9 in.
S. herbacea, a prostrate species whose branches root where they touch the soil. Yellow catkins. April. 2 in.
S. reticulata, a rare native of Scotland, with semi-prostrate branches,and oval yellow catkins. April and May. 6 in.
S. retusa, a. dwarf creeping species with twisted branches hugging the ground, and yellow catkins. S. r. serpyllifolia is an even dwarfer form. April and May. 1 in.