Acer 66 1 



in the latter case, with the two basal lobes very small and directed downwards ; 

 membranous ; shining, green, and glabrous on both surfaces, except for pubescent 

 tufts in the basal axils beneath ; petiole containing latex. 



Flowers in corymbs, appearing with the leaves, yellow or greenish -yellow, 

 variable as regards the pubescence of the calyx and the relative length of the 

 petals and sepals. Fruit, variable as regards the length and divergence of the 

 wings. 



Acer pictum is the representative in Asia of A. platanoides, and is very uniform 

 in foliage, though it extends over a wide area. Owing, however, to the remarkable 

 variation in the characters of the fruit, it has been usually divided into two species, 

 which cannot be maintained,^ as there are numerous connecting links ; and the 

 different forms are best treated as geographical varieties. 



* Branchlets remaining smooth and greenish in the second year. Wings 

 of the fruit two to three times as long as the carpels. 



1. Var. colchicum {A. latum, C. A. Meyer). Asia Minor, Caucasus. 



Leaves, five- to seven-lobed, light green in colour, thin in texture. Fruit- 

 wings usually spreading at a wide angle. In the ordinary form of this variety, 

 the leaves are green on opening. This was introduced^ in 1838 by Messrs. 

 Booth of Hamburg, plants being in cultivation in the London Horticultural 

 Society's garden in 1840. 



In var. colchicum rubrtim, introduced^ in 1846, the young leaves and young 

 branchlets are deep red in colour. 



2. Var. cultratum {A. cultratum, WaUich). Persia, Himalayas, Central China. 



Leaves thicker in texture than the last, usually five-lobed, more truncate at 

 the base. Fruit usually with horizontally spreading wings. 



This was introduced * from China in 1901 by E. H. Wilson, and is in cultiva- 

 tion at Coombe Wood, where there are plants now 10 feet in height. 



3. Var. tricaudatum, Rehder.' Central China. 



Leaves, three- to four-lobed ; basal lobes small or obsolete. This is a 

 peculiar form, with leaves smaller than in the type, scarcely exceeding two 

 inches long by three inches wide; and was introduced' by Wilson in 1901. 

 Young plants at Coombe Wood are already 14 feet high and are growing very 

 vigorously. 



4. Var. tomentosulum, Rehder.' Central China. A rare form with the young 



leaves covered beneath with dense whitish tomentum. 



** Branchlets^ becoming grey or brown and fissured in the second year. 

 Wings of the fruit about \\ times as long as the carpels. 



5. Var. eu-pictum {A. pictum, Thunberg). Japan. 



Leaves darker green and thicker in texture than in var. colchicum ; lobes 



' a. Rehder, in Sargent, Trees and Shrubs, i. 178 (1905). ^ Cf. Loudon, Card. Mag. 1840, p. 632. 



' Nicholson, Gard. Chron. xvi. 375 (i88l). ^ Joum. Roy. Hort. Soc. xxix. 354, f. loi (1904). 



* In Sargent, Trees and Shrubs, i. 178(1905). ^ Journ. Roy. Hort. Soc. xxix. 354, fF. 100, 102 (1904). 



' Rehder, loc. cit., points out that this character b inconstant, as he has found in several Japanese specimens the bark of 

 the branchlets similar in colour to that of var. colchicum. 



