ENUMERATION OF THE SPECIES 41 



displays. The flowers last longer and are seen to best advantage when growing in 

 the partial shade of conifers and other evergreen plants. In full sun the flowers bleach 

 and fade more quickly. In the Arnold Arboretum the leaves are quite deciduous. 

 This Azalea is the only kind with red flowers hardy in this Arboretum and is one 

 of the most valuable exotic flowering plants ever brought into cultivation in eastern 

 North America. 



A form with white flowers is: — 



Rhododendron obtusum var. Kaempf eri f . albiflorum Wilson, n. name. 



Rhododendron Kaempferi f. album Nakai in Tokyo Bot. Mag. XXIX. [261] 

 (1915). 



Unknown to me and described in Japanese only. Presumably normal except 

 for its white flowers but possibly the same as the f . monstrosum Wilson. 



A form with vari-colored flowers is: — 



Rhododendron obtusum var. Kaempferi f. multicolor Wilson, n. f. 



Japan : Hondo, prov. Yamaguchi, round Ajisu, May 17, 1917, 

 E. H. Wilson (No. 8420 type, 8421, 8422, 8423, 8419, 8418, 9417, 

 8416); same locality, September 28, 1918, E. H. Wilson (No. 10,959 

 seeds only); between Habu and Asa, May 7, 1918, E. H. Wilson 

 (No. 10,368); prov. Mikawa, round Futagawa, May 9, 1918, E. H. 

 Wilson (No. 10,347). 



This form differs from Kaempfer's Azalea in its vari-colored flowers which 

 range from pale pink, salmon or mauve to purple and magenta. Some of the shades 

 are exquisite and scarcely two companion bushes have flowers of identical color. 

 In size the flowers vary slightly, and those of No. 10,368 are from 1.5 to 2.5 cm. 

 across and no larger than those of some plants of the f . japonicum. In fact this 

 new form is the link connecting the var. Kaempferi with the wild f . japonicum. 

 In certain localities this multi-colored form is abundant, as in those cited, and 

 also round Tajimi, near the city of Nagoya, in province Owari. Curiously, where 

 this form is plentiful the typical red-flowered Kaempferi is entirely absent or nearly 

 so. The soil around Ajisu is rotten granite, round Tajimi and Futagawa gravel 

 and brick clay; on the same formation and in the same general neighborhood 

 Kaempfer's Azalea grows in great plenty. On Nishi-Kirishima, where the many- 

 colored f. japonicum and the typical var. Kaempferi both grow, the soil is vol- 

 canic ashes and detritus. It is plain, therefore, that soil has nothing to do with the 

 variation in the color of the flowers, neither has altitude nor exposure. The cause 

 would appear to be innate and not due to external conditions. 



I collected much seed of this new form from the neighborhood of Ajisu, and this 

 has been distributed in England and in this country by the Arnold Arboretum, and 

 many plants have been raised. If it should prove hardy this form may prove the 

 forerunner of a new race of welcome colors among hardy Azaleas. 



A form with double flowers is: — 



Rhododendron obtusum var. Kaempferi f . plenum Wilson, n. comb. 



Rhododendron Kaempferi var. plenum Nakai in Tokyo Bot. Mag. XXIX. 

 [261] (1915). 



