Of the almost innumerable species and varieties of Salix, it is only a few that need be mentioned here for their beauty when in flower. So far as I have been able to judge, the most ornamental of the Willows in catkin time is Salix smithiana, known also as S. mollissima. This tree flowers about mid-March, producing its shortish, thick male catkins in very great abundance; the numerous exposed anthers give a soft but glowing yellow tone to the tree, and entitle it to rank as one of the most ornamental of early-flowering trees. The pendulous variety of Salix Capræa is known as the Kilmarnock Willow. Although of weeping habit it is somewhat stiff in character; but towards the end of March and later it is exceedingly pretty loaded with its grey catkins. The flowers of the typical S. Capræa (the Goat Willow) are commonly known in many country places as Palm, and are used for decorating churches on Palm Sunday. The slender, coloured twigs of the Purple Willow (Salix purpurea) bear red or purplish-tinted catkins in early April. Salix stipularis may also be mentioned for its beauty when in flower.
Alders
With the exception of a few species, such as Alnus nitida and A. maritima, which flower in September and October, all the Alders develop their blossoms in February and March. The common Alder (A. glutinosa) and its varieties are perhaps as ornamental as any at that time. Like the Willows, they look best and grow best in association with water. In such a position an Alder at that time, leafless, but laden with its slender, greenish-yellow catkins, is a beautiful object, and characteristic, too, of our English landscape. Other species possessing a similar quiet beauty are Alnus incana, A. viridis, A. oregona, and especially A. cordifolia with its green and yellow catkins.
Japanese Walnuts
Juglans sieboldiana and its close allies, J. mandschurica and J. cordiformis, do not flower till May, but bear at that time very remarkable male catkins. I have measured them over one foot long, and hanging as they do in goodly number from the branches, perfectly straight and cylindrical, they have a very striking appearance, although green. All three species are alike in their catkins, but differ in the shape of the nuts. They are noteworthy, too, for the imposing character of their foliage. The leaves are pinnate, and on young trees grown in good soil are frequently three feet long. They certainly deserve the notice of planters.
Garrya elliptica
From all the catkin-bearers hitherto mentioned, this differs in being evergreen. It is also far removed from them in relationship, and is closely allied to the Cornels. At the same time the catkins in external characteristics are very similar. Not only the catkins but the plants themselves are unisexual, and, as is usual with the catkin-bearers, it is the male that is most ornamental. These catkins are from four inches to eight inches long, and I have heard of (but not seen) them as much as one foot in length. The time at which the flowers expand depends, as with all the early catkin-bearers, on the mildness of the season. This year on a wall the catkins have been in beauty ever since the first week of January. They are very attractive in their grace and quiet beauty. Chiefly of soft grey and green colours, the bracts are, however, suffused with a warmer reddish tint. In the neighbourhood of London Garrya elliptica is quite hardy in ordinarily sheltered positions, but does not flower so freely as against a south wall. As it is of Californian origin this is not surprising. This shrub resents disturbance at the root, and in transplanting great care is necessary.
There are other species of Garrya in cultivation, but they are more suitable to the south-western counties than to the average climate of Britain.
To the catkin-bearing family belong several other well-known trees, such as the Birches, Hornbeams, and Sweet Chestnut; but flowering later in the year their beauty is apt to pass without notice in the great flush of bloom that comes in with April. The beautifully fragrant Sweet Gale must not be passed without mention. Its reddish brown catkins are formed before autumn, and expand on the still leafless twigs in spring.