RHODODENDRON 337 



azaleas or mainly deciduous group it would be difficult to find a rival. 

 The leading characteristics of the genus in its broader sense are as 

 follows: Shrubs or small trees, deciduous or evergreen; leaves alternate, 

 simple, entire ; flowers in usually terminal but sometimes axillary clusters 

 or short racemes, or solitary ; corolla variable in shape, and either saucer- 

 shaped, funnel-shaped, bell-shaped, or tubular, usually five-, sometimes 

 six- to ten-lobed, white, yellow, many shades of purple and red, never 

 real blue ; calyx usually five-lobed, sometimes almost or quite obsolete ; 

 stamens five to twenty; seed-vessel dry, woody, splitting longitudinally; 

 seeds numerous, minute, and winged. 



The true species of the evergreen group are now largely superseded 

 in gardens by the varieties of hybrid origin which originated mainly from 

 catawbiense, ponticum, arboreum, and caucasicum, and to a smaller 

 extent from maximum, Griffithianum, Fortunei, and Thomsoni. The 

 same is the case with the deciduous or azalea group. Here the original 

 wild types, from which the beautiful garden or so-called "Ghent" 

 varieties were obtained by hybridisers, are flavum, calendulaceum, nudi- 

 florum, viscosum; and latterly, occidentale, molle, and sinense. Many 

 of these azaleas give beautiful autumn colour. 



The hardy species are confined to the northern hemisphere, and the 

 greatest aggregation of species occurs in the Chinese-Thibetan-Himalayan 

 region. Eight or nine are found in Europe and Asia Minor, about a 

 dozen (mostly azaleas) in N. America, somewhat more in Japan. A 

 sub-tropical group with which we have here no concern belongs to the 

 East Indies, New Guinea, and Australia. 



In the identification and differentiation of the numerous species the 

 shape and size of the calyx and corolla play a great part, as does also the 

 length of the stamens in relation to the corolla and style. The presence 

 or absence of scales on the younger parts of the plants (a condition known 

 as " lepidote "), and the presence or otherwise of down or glands on the 

 shoots, leaves, calyx, stamens, ovary and style, are also valuable points 

 in assisting identification. 



Cultivation. The cultivation of pretty nearly all rhododendrons is 

 the same, and the only difference between the deciduous and the ever- 

 green ones is that the former like more sun. Some of the evergreen 

 species and varieties do very well in semi-shade. In this connection 

 Mr E. H. Wilson told me that he found in China the large broad-leaved 

 species grew naturally in shade ; the small-leaved, scaly, resinous ones on 

 the mountain tops in full sun, filling the same place there as heather on 

 British moors. But in our climate there are very few species or 

 varieties that will not thrive in full sunlight. All those that flower in 

 early spring, and thus become liable to injury by frost, are best in 

 positions shaded from the morning sun. In such spots they have a 

 chance to thaw gradually, and escape the entire destruction that awaits 

 those flowers exposed to the full rays of the bright early sunshine that 

 so frequently follows a frosty night. But as a rule 5 or 6 of frost 

 is fatal to the expanded flowers of rhododendrons. Both rhododen- 

 drons and azaleas are especially suited for planting in large masses. 

 Where the garden is large enough special areas may be set apart foi 



