Acer 635 
» 
rounded, short, obtuse or acute; margin with small irregular teeth; petiole 
without latex. In var. neapolitanum, the leaves (Plate 206, Fig. 15) are more 
obscurely lobed, with very dense long pubescence beneath. (See description, 
p. 663.) 
21. Acer grandidentatum, Nuttall. Montana southwards to New Mexico. 
Leaves (Plate 205, Fig. 4) 3 inches long, 4 inches broad, with three large 
oblong lobes, separated by sinuses extending half-way to the base, of the blade ; 
margin with a few large obtuse lobules, otherwise entire; under surface covered 
with pale dense pubescence; basal lobes represented by the lowest pair of the 
marginal lobules. 
A small tree, rarely forty feet in height, representing the sugar maple in the 
West. There is a small specimen thriving in the Kew Collection. 
22. Acer rubrum, Linnzeus. North America. 
Leaves (Plate 207, Fig. 27) averaging 3 inches long and broad, variable in 
shape; under surface silvery white with scattered pubescence; lobes usually 
triangular, acute or acuminate, sharply toothed or bi-serrate in margin; sinuses 
acute at the base, variable in depth; base of the leaf truncate or rounded, 
rarely cordate. (See description, p. 671.) 
23. Acer tetramerum,' Pax. Central China. 
Leaves 3 inches long, 2 inches broad, ovate, cordate at the base, indistinctly 
five-lobed ; basal lobes obscure or obsolete ; lateral lobes short, triangular, acute 
and sharply serrate; terminal lobe with two or three pairs of serrated teeth, 
and prolonged into a long narrow acuminate apex ; margin ciliate ; upper surface 
dark - green, scattered pubescent; lower surface pale, covered with white 
pubescence, densest in the axils ; petiole without latex. 
A small tree, introduced by Wilson in 1901. Young plants at Coombe 
Wood are perfectly hardy and free in growth, having already attained 16 feet 
in height. 
IV. Leaves five-lobed ; basal lobes well-developed ; white or pale beneath ; petiole 
without latex. 
* Leaves not serrate. 
24. Acer Opalus, Miller. Southern Europe. 
Leaves (Plate 206, Fig. 14) 24 inches long, 3 inches wide ; lobes short, acute, 
irregularly toothed; under surface with scattered pubescence, denser on the 
nerves and forming axil-tufts. (See description, p. 663.) 
25. Acer saccharum, Marshall. North America. 
Leaves (Plate 206, Fig. 12) 5 inches long, 6 inches wide; lobes triangular, 
acuminate, with one or two pairs of sinuate teeth; lower surface with axil-tufts 
of pubescence, elsewhere glabrous or more or less pubescent. (See description, 
p. 677.) 
26. Acer hyrcanum, Fischer et Meyer. South-Eastern Europe, Crimea, Asia 
Minor, Caucasus. 
1 Cf. J. H. Veitch, Journ. Roy. Hort. Soc. xxix. 353, fig. 97 (1904). 
III 2B 
