174 THE AZALEAS OF NORTH AMERICA 



R. calendulaceum, R. nudiflorum, R. speciosum, R. viscosum and the 

 Old World R. luteum. An interesting hybrid was raised by the Rev. 

 William Herbert at Spofforth by crossing R. luteum and R. canadense, 

 the species representing two different sections; it was figured by Lind- 

 ley in 1838 as Azalea Seymouri, but apparently disappeared soon 

 from cultivation, as it had no particular ornamental merits. 



After R. molle G. Don (Azalea sinensis Lodd.), introduced in 1823 

 from China, had found its way into the gardens it also was used to pro- 

 duce new hybrids, and a hybrid with R. viscosum was figured as Azalea 

 altaclarense in 1842, one with R. speciosum as Azalea marginata in 1835 

 and one with a form of R. Mortieri was figured in 1845 as A. sinensis 

 var. Bylsiana. The influence of R. molle, however, does not seem to 

 have left a perceptible trace among the older Azalea hybrids, but 

 when crossed with R. occidentale A. Gray introduced about 1850, 

 which was used by Anthony Waterer of Knap Hill and by others in 

 hybridization work with this and other hardy Azaleas, a very hand- 

 some race of hardy free-flowering Azaleas with large flowers of prevail- 

 ingly light colors was developed, classed here under R. albicans. A 

 still greater influence on the development of hybrid Azaleas took place 

 when R. japonicum was introduced into the gardens in the early six- 

 ties. It became soon widely known under the name Azalea mollis 

 and by hybridizing it with other hardy Azaleas a distinct race known 

 as " Azalea mollis hybrids " (R. mixtum) was raised, characterized 

 by low compact habit and dense clusters of large scentless flowers 

 with a wide limb and short tube. Among the " Mollis hybrids " are 

 often included the hybrids of R. japonicum with R. sinense for which 

 the name R. Kosterianum has been proposed; the first hybrids of this 

 kind appear to have been raised in the seventies (see p. 97). About 

 1890 another race of hybrids was raised by crossing R. japonicum 

 with evergreen Rhododendrons (see p. 99) ; these were called by Andre" 

 " Azaleodendron." Recently an interesting hybrid between two dif- 

 ferent sections was raised by G. Fraser of Ucluelet, Vancouver, B. C, 

 by crossing R. japonicum with R. canadense. This promises to be a 

 very ornamental plant unlike the older R. Seymouri, the first known 

 hybrid of R. canadense. 



In the following enumeration the different garden forms are placed 

 under their supposed parents, though in many cases it is not certain 

 whether the parentage given in the original description or the opinion 

 based on the evidence presented is correct. If an available binomial 

 exists, it follows the indication of the parentage and is printed in 



