SAPINDACE. SILVA OF NORTH AMERICA. 93 
ACER CIRCINATUM. 
Vine Maple. 
FLOWERS in terminal umbel-like corymbs; petals involute, much shorter than the 
sepals. Leaves palmately 7 to 9-lobed. 
Acer circinatum, Pursh, Fl. Am. Sept. i. 266. — Poiret, 1851, 791, f. 210.— Newberry, Pacific R. KR. Rep. vi. 21, 
Lam. Dict. Suppl. v. 669. — Nuttall, Gen. i. 253; Jour. 69. — Cooper, Pacific R. RK. Rep. xii. 28, 57. — Lyall, 
Phil. Acad. vii. 17 (excl. syn.); Sylva, ii. 80, t. 67. — Jour. Linn. Soc. vii. 1384.— Gray, Proc. Am. Acad. viii. 
De Candolle, Prodr. i. 595. — Sprengel, Syst. ii. 225. — 379. — Koch, Dendr. i. 523. — Torrey, Bot. Wilkes Ex- 
Don, Gen. Syst. i. 651. — Loudon, Arb. Brit. i. 422, £. plor. Exped. 258. — Brewer & Watson, Bot. Cal. i. 107. — 
112.— Spach, Ann. Sci. Nat. ser. 2, ii. 169; Hist. Veg. G. M. Dawson, Canadian Nat. n. ser. ix. 330. — Sargent, 
iii. 97. — Torrey & Gray, Fl. N. Am. i. 247. — Hooker, Forest Trees N. Am. 10th Census U. S. ix. 47. — Pax, 
Fl. Bor-Am. i. 112, t. 39. — Dietrich, Syn. ii. 1282. — Engler Bot. Jahrb. vii. 203. — Wesmael, Gen. Acer, 25. 
Lindley, Paaton Fl. Gard. ii. 156, f. 210; Gard. Chron. A. virgatum, Rafinesque, New F7. i. 48. 
A low tree, rarely thirty or forty feet in height, often vine-like or prostrate, with a trunk ten or 
twelve inches in diameter covered with thin smooth bright red-brown bark marked by numerous shallow 
fissures ; or often a low wide-spreading shrub. The branchlets are glabrous, sometimes pale green and 
sometimes reddish brown, frequently covered late in the season and during their first winter with a 
glaucous bloom, and occasionally marked with small lenticular spots. The winter-buds are an eighth of 
an inch long, rather obtuse, and furnished at the base with a short brown papery subpetiolar scale with 
ciliate margins. The outer bud-scales are rounded on the back, rather thin, and bright red; they 
inclose a pair of thick scales coated with dense white tomentum which protect the inner series; these are 
green in the bud and lengthen with the growing shoot until at maturity they are two inches long, a 
quarter of an inch broad, obovate-spatulate, rounded at the apex, contracted into a long narrow claw, 
bright rose-colored, and more or less hairy-pubescent, especially on the outer surface. The leaves are 
almost round in outline, palmately seven to nine-lobed sometimes nearly to the middle, with acute lobes 
sharply and irregularly doubly-serrate ; they are conspicuously palmately-nerved with prominent veinlets, 
and are cordate at the base by a broad shallow sinus, or sometimes almost truncate, two to seven inches 
across, and borne on stout grooved petioles one or two inches long which clasp the stem by their large 
bases; they are tinged with rose-color when they unfold and are then somewhat puberulous, principally 
on the lower surface and the petioles, but at maturity are glabrous with the exception of a tuft of 
pale hairs in the axils of the large veins on the upper surface ; they are thin and membranaceous, dark 
green above and paler below, and in the autumn turn orange and scarlet. The flowers appear when 
the leaves are about half grown in loose ten to twenty-flowered umbel-like corymbs drooping on long 
stems from the ends of slender two-leaved branchlets, the staminate and pistillate flowers being produced 
together. The sepals are oblong or obovate, acute, villous, purple or red, and much longer than the 
greenish white broadly cordate acute petals which are folded together at the apex. There are from six 
to eight stamens with slender filaments villous at the base, exserted in the sterile flower, and in the fertile 
flower shorter than the petals. The ovary is glabrous with spreading lobes, and is surmounted by a 
style divided near the base into long exserted stigmas; in the staminate flower it is reduced to a small 
point surrounded by a tuft of pale hairs. The fruit is two or three inches long with thin wings which 
spread almost at right angles to the peduncle and, like the nutlets, are red or rose-colored in early sum- 
mer, when the fruit is fully grown, although it does not ripen until late m the autumn. The seed is 
ovate, with a pale chestnut-brown testa and foliaceous cotyledons. 
