Acer. SAPINDACE^. 



107 



between Monterey and Clear Lake, it is a widely branched tree, the base much expanded and oc- 

 casionally 6 feet in diameter, the trunk half as large and branching low, the main branches 1 to 

 2 feet thick, the whole forming a dense head 25 to 40 feet high and of still greater breadth. lu 

 May, when in full flower, it is a beautiful tree, but the leaves often fall before midsummer, so 

 that for much of the year it is bare. Usually only two or three flowers in each thyrse i^rfect 

 their fruit, often but one. The wood is soft and brittle. 



2. ACER, Tourn. Maple. 



Flowers polygamo-dioecious. Calyx colored, usually 5-lobed. Petals as many or 



none. Stamens 3 to 12, usually 8, inserted with the petals upon a lobed disk. 



Ovary 2-lobed, 2-celled : ovules a pair in each cell : styles 2, elongated. Fruit a 



double samara or key, divaricately 2-winged above, separable at maturity, each 



1-seeded. Albumen none. Cotyledons large and thin, variously coiled or folded. 



— Trees or shrubs ; leaves opposite, palmately lobed (in American species), without 



stipules ; flowers small, in terminal racemes, umbel-like corymbs, or fascicles, the 



pedicels not jointed. 



About 50 species, mostly of tlie northern hemisphere. Of the 9 species of the United States 

 5 are confined to the Atlantic States, some of "them valuable forest trees and extensively planted 

 for shade and ornament. The other species of the Rocky Mountains and westward are of far less 

 importance. The wood in general is hard and close-grained, and sugar is made from the sap of 

 several species. 



* Flowers ill racemes : body of the fruit hisjiid. 



1. A. macrophyllum, Pursh. A tree, 50 to 90 feet high, 2 or 3 feet in diam- 

 eter : leaves G to 10 inches broad or more, pubescent when young, becoming gla- 

 brate, cordate witli a deep narrow sinus, deeply 3-5-cleft; tlie segments sinuate with 

 2 or 3 acute lobes : flowers large, numerous, fragrant, yellow, in crowded pendulnus 

 racemes 3 to 6 inches long, appearing after the leaves : calyx 2 or 3 lines long : 

 petals oblong : stamens 9 or 10, with hairy filaments : fruit densely hairy, the 

 glabrous wings 15 to 20 lines long and more or less divergent. — Hook. Fl. i. 112, 

 t. 38; Nutt. Sylva, ii. 77, t. 67; Newberry, Pacif. R. Rep. vi. 21. 



In mountain ravines from Santa Barbara to Fraser River ; in California mostly confined to the 

 ranges along the coast and not so large as in Oregon, where it is sometimes found five feet in diam- 

 eter and valuable for its timber. The wood is white, hard, and takes a fine polish. The bark of 

 the trunk is light gray, on the younger branches green with stripes of lighter color. 



% =k Flowers in loose umhei-like corymbs : fruit smooth. 



2. A. circinatum, Pursh. (Vine-Maple.) A shrub or small tree : leaves 3 to 

 5 inches broad, shortly petioled, somewhat villous, at length glabrous, with usually 

 a tuft of hairs at the base, rounded-cordate with a broad and often shallow sinus, 



7 - 9-lobed nearly to the middle ; the lobes acuminate, sharply serrate : corymbs 

 loosely 10-20-flowered, terminal on slender 2-leaved branchlets : sepals red or pur- 

 ple, villous, 2 or 3 lines long, much exceeding the greenish-white petals : stamens 



8 ; filaments villous at base : fruit 10 to l-i lines long, the wings spreading at right 

 angles to the peduncle. — Hook. Fl. i. 112, t. 39; Nutt. Sylva, ii. 80, t. ^S ; New- 

 berry, Pacif. R. Rep. vi. 21. 



Northern California, in pine forests, and northward to British Columbia ; in this State a more 

 shrub, in Oregon sometimes a tree 30 or 40 feet high. In moist places and on ricli alluvial soils 

 it often takes complete possession, the vine-like stems growing in clusters from the same root, and 

 tliemselves striking root wherever they touch the gi-ound and sending out numerous olfshoots. 

 Thus interlaced and fastened together they form dense dark thickets almost impenetrable. The 

 wood is heavier and closer-grained than in the last species. 



3. A. glabrum, Torr. A shrub or small tree : leaves glabrous, 2 to 4 inches 

 broad, rounded-cordate in outline with a shallow sinus, laciniately 3 -5-lobed, more 

 or less deeply or sometimes completely 3-parted ; the lobes doubly-serrato with very 



