178 ALBIZZIA ALNUS 



The species is not hardy at Kew in the open, but grows very well on a 

 lofty wall, where its large, beautifully divided leaves give a very pleasing 

 effect in the height of summer. In such a spot it is well to plant some 

 other climber, preferably evergreen, to grow over the lower part of the 

 wall beneath the Albizzia, which grows quickly in its younger stages and 

 leaves its base naked. 



ALNUS. ALDERS. BETULACE^:. 



The alders are deciduous trees and shrubs closely allied to, and only 

 likely to be confounded with, the birches (Betula). Leaves with stipules, 

 alternate, more or less toothed in all the cultivated species. Winter buds 

 nearly always stalked. Male and female flowers borne on the same tree 

 but on separate catkins. Male catkins long and slender, usually in 

 clusters of two to six; the flowers small, with a four-lobed calyx, no 

 petals, and usually four (sometimes one to three) stamens. Female 

 catkins shorter, clustered, or rarely solitary, developing into woody, cone- 

 like fruits, known as strobiles, ^ to over i- in. long. The seed is a minute, 

 flattened nutlet, often with thin membranous wings at the sides. With 

 the exception of two species A. maritima and A. nitida which flower 

 in autumn, the cultivated alders form their catkins in the late summer and 

 autumn ; these expand the following spring, either very early before the 

 leaf-buds begin to grow, or along with the leaves; the fruits develop 

 during the summer and persist until the succeeding spring. From the 

 alders the birches are distinguished by the fruits being longer, not woody, 

 and falling to pieces (those of the alders falling whole), and the flowers 

 of birches have never more than two stamens. 



In gardens and parks the alders are chiefly valuable for growing in 

 wet situations unsuited to the majority of trees. Some, however, such as 

 A. japonica, nitida, and firma, succeed quite well in ordinary good soil. 

 All are best propagated by seed except the garden varieties, which may be 

 grafted on their respective types, or, better still, rooted from cuttings 

 made as soon as the leaves fall, and put in sandy soil, as willow or poplar 

 cuttings are compared with which, however, they do not strike root 

 so readily. The following is a selection of the best worth growing, 

 irrespective of their use in damp places: Cordifolia, firma, nitida, 

 oregona ; glutinosa var. imperialis and var. incisa ; incana var. incisa and 

 var. ramulis coccineis. 



A. BARBATA, C. A. Meyer. 



(A. glutinosa var. barbata, Ledebour.*) 



A tree nearly related to A. glutinosa, and with the same general aspect, but 

 quite distinct in the very downy shoots. Leaves oval or ovate, rounded at the 

 base and either rounded or pointed at the apex, doubly toothed ; 2 to 3^ ins. 

 long, i^ to i\ ins. wide ; dark glossy green above, downy beneath, especially 

 on the veins and midrib ; veins in eight to ten pairs ; stalks \ to f in. long, 

 downy. 



Native of the Caucasus, uncommon in cultivation, but represented by a 

 tree on the east side of the lake at Kew, now 20 ft. high. It is sometimes 



