672 The Trees of Great Britain and Ireland 



the under surface, like the young branchlets and petioles, with hoary tomentum. 

 Flowers and fruit bright scarlet. The variety is found in deep river swamps of 

 Southern Arkansas, Eastern Texas and Western Louisiana. 



2. Var. tridens, Wood.' Leaves three-lobed at the apex, rounded or cuneate 

 at the base, thick and firm in texture, serrate except towards the base with remote 

 incurved glandular teeth. Flowers sometimes yellow ; fruit usually much smaller 

 and rarely also yellow. This variety occurs in the coast region from Southern New 

 Jersey to Southern Florida, and along the Gulf Coast to Eastern Texas. 



A large number of varieties, based on trivial characters, are given by Pax 

 and von Schwerin as occurring in cultivation, the most noteworthy of which is var. 

 sanguineum, with the leaves deeper green above, bluish-white beneath, and turning 

 a brilliant red in autumn. In cultivated trees in England there are marked 

 differences in the size and shape of the leaves and in the amount of pubescence on 

 their under surface ; but these differences are not worth naming. Columnar and 

 bushy rounded forms are known ; and a pendulous form is also mentioned in the 

 Kew Hand List, which seems, however, to be a form of A. dasycarpum. 



(A. H.) 



Distribution 



In America this tree is one of the commonest and most widely distributed, 

 extending from about lat. 49 N. in Quebec and Ontario, south to Florida and west 

 to Wisconsin, Iowa, and the Trinity river in Texas ; abundant in the Mississippi 

 valley, and attaining its largest size on the lower Ohio and in the Wabash valley, 

 where Ridgway measured a tree 108 feet by 15 feet, with a clean bole 60 feet 

 long, and says that larger trees could be found. In New England it grows 

 abundantly in swamps and low ground, and is usually a tree of no great size, so far 

 as I have seen. Emerson records no large trees, while Michaux says that he 

 nowhere saw it larger than in the swamps of New Jersey and Pennsylvania, where 

 it is often 70 feet high and 3 to 4 feet in diameter. It is the earliest tree in flower 

 and was nearly over in the middle of May, near Boston, when the leaves were partly 

 developed. Emerson says that they vary remarkably in size and shape, being some- 

 times broad and five-lobed, sometimes long and narrow, and are liable to become of 

 a scarlet, crimson, or orange colour at all seasons, sometimes at midsummer, long 

 before other trees have changed colour. He thinks that the frost has little to do 

 with the autumnal coloration of leaves, and that the greater intensity of the light 

 and transparency of the air is the reason why the leaves of trees usually turn so 

 much more brilliant in colour in America than in Europe. 



A fastigiate tree of this species is illustrated in Garden and Forest, vii. 65 

 (1894), where it is erroneously^ called a sugar maple. It grows in the grounds of 

 Mrs. Leavitt at Flushing, New York, and is 80 feet high. Sargent adds that only 

 two other American trees, the tulip tree and the Robinia, are known to have 

 produced forms with fastigiate branches. 



' Cf. Rehder, in Rhodcra, ix. Il6 (1907). 

 ' Mr. W. A. Stiles, in a letter to Kew, dated March 28, 1894, corrects this error. 



