SAPINDACEZ. SILVA OF NORTH AMERICA. 85 
ACER PENNSYLVANICUM. 
Striped Maple. Moose Wood. 
FLOWERS in long drooping racemes; petals obovate, as long as the sepals; ovary 
and young fruit glabrous. Leaves 3-lobed at the apex. 
Acer Pennsylvanicum, Linnzus, Spec. 1055. — Michaux, 245. — Watson & Coulter, Gray’s Man. ed. 6, 117. — 
fl. Bor.-Am. ii. 252. — Willdenow, Spec. iv. 989; Enum. Wesmael, Gen. Acer, 46. 
1045. — Desfontaines, Hist. Arb. i. 391. — Nouveau Du- A. Canadense, Marshall, Arbust. Am. 3. 
hamel, iv. 32. — Trattinick, Archiv. i. t. 11.— Hayne, A. striatum, Du Roi, Diss. 58; Harbk. Bawm. i. 8, t. 1.— 
Dendr. Fl. 210. — Elliott, Sk. i. 451. — Torrey, Fl. N. Wangenheim, Nordam. Holz. 29, t. 12, f. 28. — Castigli- 
Y. i. 185.— Sprengel, Syst. ii. 224. — Torrey & Gray, oni, Viag. negli Stati Uniti, ii. 172. — Lamarck, Dict. ii. 
Fl. N. Am. i. 246. — Hooker, Fl. Bor.-Am. i. 111. — 381. — Ehrhart, Beitr. iv. 25. — Schmidt, Oestr. Bawm. 
Gray, Gen. Ill. ii. 200, t. 174, £. 1-3. — Chapman, FV. i. 13, t. 10.— Moench, Meth. 56.— Persoon, Syn. i. 
80. — Curtis, Rep. Geolog. Surv. N. Car. 1860, iii. 52. — 417. — Michaux f. Hist. Arb. Am. ii. 242, t. 17. — Pursh, 
Buchenau, Sot. Zeit. xix. 285, t. 11, £. 24. — Koch, Dendr. Fl. Am. Sept. i. 267. — Nuttall, Gen. i. 253. — De Can- 
i. 521. — Baillon, Hist. Pl. v. 373, £. 418-420. — Em- dolle, Prodr. i. 593. — Watson, Dendr. Brit. ii. t. 170. — 
erson, Trees Mass. ed. 2, ii. 566, t. — Bell, Geolog. Rep. Don, Gen. Syst. i. 648. — Loudon, Ard. Brit. i. 407, t. — 
Canada, 1879-80, 53°.— Sargent, Forest Trees N. Am. Spach, Ann. Sez. Nat. ser. 2, ii. 162; Hist. Veg. iii. 
10th Census U. S. ix. 46. — Pax, Engler Bot. Jahrb. vii. 85. — Dietrich, Syn. ii. 1281. — Bigelow, Fl. Boston. ed. 
3, 407. 
A small tree, thirty or forty feet in height, with a short trunk eight or ten inches in diameter and 
slender upright branches; or often much smaller and shrubby in habit. The bark of the trunk varies 
from an eighth to a quarter of an inch in thickness and is reddish brown, marked longitudinally with 
broad pale stripes, and roughened with numerous horizontal oblong excrescences. The branchlets are 
pale greenish yellow, very smooth, and at first change little in appearance except to turn bright reddish 
brown during the winter when they are exposed to the action of the sun; but at the end of two or three 
years become striped like the trunk, with broad pale marks. The terminal winter-bud is conspicuously 
stipitate, and when it contains an inflorescence is almost half an inch long and much longer than the 
axillary buds; it is covered by two thick bright red spatulate boat-shaped scales prominently keeled on 
the back and inclosing a second pair of scales densely coated with white tomentum; the inner scales 
are green and foliaceous, and enlarge with the young shoots until they are an inch and a half or two 
inches long and half an inch wide when they are pubescent and bright yellow or rose-colored; in 
falling they leave two or sometimes three conspicuous narrow scars surrounding the base of the branches. 
The leaves are palmately three-nerved, three-lobed at the apex, rounded or cordate at the base, and 
finely and sharply doubly serrate, the short lobes contracted mto tapering serrate points ; they are five 
or six inches long and four or five inches broad, and are borne on stout grooved petioles an inch and a 
half to two inches in length, the enlarged bases of each pair nearly uniting and embracing the branch. 
The leaves, when they first appear, are thin and membranaceous, pale rose-colored, and coated with 
ferrugineous pubescence, especially on the lower surface and petiole. This gradually disappears, and 
at maturity the leaves are glabrous with the exception of a tuft of ferrugineous hairs in the axils of the 
principal nerves on the upper surface, membranaceous, pale green above and rather paler below. In 
the autumn they turn a clear bright yellow. The flowers unfold towards the end of May or in early 
June when the leaves are nearly fully grown; they are borne in slender drooping long-stemmed racemes 
from four to six inches in length, the sterile and fertile flowers being usually produced on different 
racemes on the same plant. The pedicels are thread-lke, and vary from a quarter to half an inch 
