342 RHODODENDRON 



half as wide ; glossy green and smooth above except on the midrib ; pale, 

 glaucous, and smooth beneath ; margins edged with minute bristles. Flowers 

 fragrant, i-| ins. long. 2 to 2j ins. wide, white tinged with pink ; corolla-tube, 

 hairy-glandular, the lobes spreading ; stamens five, bright red, much 

 protruded ; style still longer ; flower-stalk 3- in. long, smooth, or sometimes 

 bristly ; calyx-lobes linear, to J in. long, very bristly. 



Native of Eastern N. America in mountainous regions ; discovered by 

 John Bartram, and introduced in 1818. This azalea, although now but little 

 known, is one of the most beautiful of its kind, and is valuable in flowering 

 late (June and July) when the plants have become leafy. It is allied to 

 R. viscosum (whose flowers also expand after the young leaves), differing in its 

 larger size, in the shining, smooth foliage, and in the only slightly sticky 

 corolla tube. In drying, the foliage acquires a perfume like that of 

 mown grass, 



R. AREOREUM, Smith. 



A small evergreen tree ultimately 30 to 40 ft. high, with a thick, sturdy 

 trunk, the branches forming a head as wide as the tree is high, and reaching 

 to the ground. Leaves narrowly oblong, tapering at both ends ; 4 to 7 ins. 

 long, i to 2 ins. wide ; smooth above, covered beneath with a coat of silvery 

 scales ; stalk \ to i in. long. Flowers blood red, borne in a compact hemi- 

 spherical head", 4 to 5 ins. through, sitting close on the terminal whorl of 

 leaves. Corolla bell-shaped, i| to 2 ins. across ; stamens ten ; calyx very 

 small ; flower-stalk downy. 



Native of the outer Himalaya, where it is widely spread ; introduced in 

 1817. This species is one of the most variable of all rhododendrons, but the 

 form just described, with crimson flowers and silvery under-surface of the 

 leaves, may be taken as the type. There are, besides, other forms with leaves 

 covered with a rich reddish felt beneath, and flowers ranging in colour from 

 rosy red to nearly white. Some of these have distinctive names : 



Var. ALBUM. Flowers white ; leaf rust-coloured beneath. 



Var. CAMPBELLI/E. Flowers purplish rose ; leaf reddish beneath. 



Var. CINNAMOMEUM. Flowers almost white ; leaf reddish beneath. 



Var. LIMBATUM. Flowers rosy purple ; leaf silvery beneath. 



Var. NILAGIRACUM. Flowers deep rose ; leaf rust-coloured beneath. 



Var. WlNDSORll. Flowers and trusses small ; deep crimson. 



Of all these forms the only one which has succeeded at Kew out-of-doors is 

 var. cinnamomeum, and that grows very slowly and flowers uncertainly. But 

 in Cornwall, S. Wales, Ireland, etc., R. arboreum in all its forms makes some 

 of the chief glories of the gardens. There is a splendid tree of Carclew, near 

 Falmouth, which, when I saw it a good many years ago, was over 30 ft. high, 

 its trunk 4 ft. in. girth. At Castle wellan, Co. Down, there is a famous specimen, 

 forming a pyramid of foliage 30 ft. high and 45 ft. through. 



R. arboreum, tender though it may be, has played an important part in the 

 evolution of the hardy garden rhododendrons as we know them to-day. All 

 the red-flowered varieties as distinct from the rose, pink, purple, and white 

 ones owe their colour to this species. They are far too numerous to be even 

 mentioned here, but a selection of the best is given in the introductory notes 

 to the genus. The following are some of the more important primary crosses : 



R. ALTACLERENSE, Lindley (Bot. Mag., 3423). Raised at Highclere, the seat 

 of the Earl of Carnarvon in Berkshire, by crossing arboreum with ponticum ; 

 it has beautiful, deep rosy red flowers in large trusses 6 ins. through. Very 

 similar to it is 



R. RUSSELLIANUM, Sweet, from catawbiense crossed with arboreum, but of 

 a more crimson shade. It is as richly coloured as all but the richest forms of 

 arboreum. Flowers in April and May. 



