1923] WILSON, THE RHODODENDRONS OF NORTHEASTERN ASIA 51 



Rhododendron dauricum var. ciliatum Wilson, n. comb. 



Rhododendron mucronulatum var. ciliatum Nakai in Tokyo Bot. Mag. 

 xxxi. 241 (1917); Fl. Sylv. Kor. pt. vm. 37, t. 11 (1919). 



This variety is distinguished by its ciliate leaves and petioles. A few 

 appressed, strigose hairs occur on the upper surface of the leaf; the flowers 

 in size are similar to those of the var. mucronulatum Maxim. The cilation 

 makes the typical form quite distinct but it varies in quantity and on some 

 plants is reduced to a few hairs on the petiole. 



Nakai, who founded the variety, gives central and southern Korea 

 including the islands of Quelpaert, Tsushima Island, western Hondo and 

 Kyushu as the range of distribution of this variety. I have seen no 

 material from Japan, but I am familiar with it in Korea and a specimen 

 from the hills round Chefoo in China is intermediate in character. On the 

 Diamond Mountains it is particularly common and from there I sent 

 seeds to the Arnold Arboretum in 1917. Plants raised from these seeds 

 flowered for the first time in 1920 under glass. The plant has proved 

 perfectly hardy in the Arnold Arboretum and its garden value would 

 appear to be the same as the var. mucronulatum Maxim. 



A variety with white flowers is 



Rhododendron dauricum var. album De Candolle Prodr. vn. 725 (1839). 



Rhododendron dahuricum 0. albiflorum Turczaninow in Bull. Soc. Nat. 



Mosc. xxi. pt. 2, 501 (Fl. Baical. Dahur.) (1848\ 

 Rhododendron mucronulatum var. albiflorum Nakai in Jour. Coll. Sci. 



Tokyo xxxi. 76 (Fl. Kor. n.) (1911); Fl. Sylv. Kor. pt. vm. 37 (1919). 



This albino form was discovered by N. Turczaninow in woods near the 

 Angara River in central Siberia sometime between 1828 and 1836. Nakai 

 quite recently found it in Korea. I have not heard of its appearance in 



our gardens. 



Of the several hybrids of which R. dauricum Linn, and its varieties are 

 part parents the first I find record of is 



X Rhododendron aprilis Lindley in Bot. Reg. xxix. t. 62 (1843). 



This was raised by Dean Herbert by impregnating R. ponticum Linn, 

 with pollen from R. dauricum var. sempervirens Sims. The figure shows 

 an evergreen Rhododendron bearing a compact truss of pale pink flowers 

 with yellow honey-guides on the dorsal segments. 



A popular hybrid is 



X Rhododendron £raecox Carriere in Rev. Hort. 1868; 211, t. (= R. 



ciliatum Hook, f . X R. dauricum Linn.). — Gard. Chron. n. s. ix. 335 (1878); 

 xvn. 295, fig. 40 (1882).— W. in Garden, xxxvin. 32, t. 761 (1890).— W. W. 

 in Gard. Chron. ser. 3, xn. 762, fig. 124 (1892). — Dallimore in Garden, 

 lix. 277, fig. (1901).— Garden, lxi. 428, fig. (1902).— W. A. Watts in 

 Garden, lxxi. 151, fig. (1907). — Bean, Trees & Shrubs Brit. Isl. II. 350 

 (1914).— Rehder in Bailey, Stand. Cycl. Hort. v. 2938 (1916). 



