636 The Trees of Great Britain and Ireland 



Leaves (Plate 207, Fig. 22) 2^ inches long, 3 inches wide; lobes oblong, 

 acute or acuminate, with one to four small teeth ; sinuses reaching half the 

 length of the blade, usually rounded at the base ; lower surface glabrous except 

 for pubescence along the nerves and forming axil-tufts. 



A small tree, representing A. Opalus in the Orient and Balkan Peninsula. 

 There are good specimens in the collection at Kew. 



27. Acer Heldreichii, Orphanides. Balkan Peninsula, Greece. 



Leaves (Plate 206, Fig. 17)* 4 inches long, 5 inches broad, deeply five-lobed ; 

 the middle sinuses narrow, acute at the base, and reaching nearly to the base 

 of the blade ; lobes acuminate, with two or three pairs of triangular teeth ; under 

 surface with brown pubescence along the primary nerves, forming axil-tufts, 

 glabrous elsewhere. 



There is a small tree of this species in the Maple Collection at Kew. 



28. Acer Trautvetteri, Medwedjefif. Caucasus. 



Leaves (Plate 206, Fig. 19) averaging 5^ inches long and 6 inches broad, 

 deeply five-lobed ; the middle sinuses acute at the base, reaching two-thirds the 

 length of the blade ; lobes long acuminate, with four or five pairs of irregular 

 teeth ; under surface glabrous except for conspicuous tufts of reddish -brown 

 pubescence in the axils, at the base, and at the junctions of the primary and 

 secondary nerves. (See description, p. 669.) 



** Leaves distinctly serrate. 



29. Acer Pseudoplatanus, Linnaeus. Europe, Asia Minor, Caucasus, Northern 



Persia. 

 Leaves (Plate 206, Fig. 20) averaging 5 inches long and 6 inches wide ; 

 lobes acuminate, coarsely and irregularly serrate and lobulate ; sinuses acute 

 at the base, and extending half-way the length of the blade ; under surface 

 pubescent along the primary nerves. (See description, p. 641.) 



30. Acer insigne, Boissier et Buhse. Caucasus, Northern Persia. 



Leaves (Plate 206, Fig. 18) resembling those of the sycamore, but usually 

 longer than broad, averaging 7 inches long and 6 inches wide ; under surface 

 with pubescence dense along the nerves, forming axil-tufts, and spreading over 

 the leaf between the nerves. (See description, p. 667.) 



31. Acer Volxemi, Masters. Central Caucasus. 



Leaves considerably larger than in the preceding species, attaining 10 to 12 

 inches in width and length, glaucous beneath, with pubescence confined to the 

 sides of the nerves. (See description, p. 668.) 



32. Acer dasycarpum, Ehrhart. North America. 



Leaves (Plate 207, Fig. 28) about 5 inches long and wide ; sinuses rounded 

 at the base, and concave on the sides, extending half-way the length of the 

 blade ; lobes long acuminate, with serrated triangular teeth or lobules ; under 

 surface silvery white, scattered pubescent, without axil-tufts. (See description, 

 p. 674.) 



' In the mountains of Greece, the leaves are smaller than is the case in trees growing in Southern Servia, Montenegro, 

 Herzegovina, and Bulgaria, and average only 2 to 3 inches in diameter. 



