202 ACERACEAE. 
Acer. Maple. 
(Family Aceraceae). 
Shrubs or round-topped trees: 
deciduous. Wood rather hard, 
brownish, diffused-porous. Twigs 
moderate, nearly terete or some- 
what 6-sided: pith round, con- 
tinuous, pale. Buds moderate, 
solitary or sometimes collaterally 
multiple, ovoid or conical, dis- 
tinctly stalked in some groups, 
with 2 or several pairs of scales. 
Leaf-scars U-shaped: bundle- 
traces 3 or occasionally 5 or 7 or 
9, or -multiplied:  stipule-scars 
lacking. The box elders are segre- 
gated frequently as Negundo or 
Rulac. 
Winter-character references:— 
Acer argutum. Shirasawa, 275, pl. 
21. <A. californicum. Schneider, 
f. 219. A. campestre. Bosemann, 
63; Fant, 42, f. 41; Schneider, 
f. 217; Ward, 1:170, f. 84; Zuccarini, 14, pl. 8. A. carpinifolium. 
Shirasawa, 278, pl. 12. <A. circinatum. Schneider, f. 218; 
Trelease (2), 101, 103, pl. 14. A. cissifolium. Shirasawa, 272, 
pl. 10. A. crataegifolium. Shirasawa, 271, pl. 10. A. disty- 
lum. Shirasawa, 275, pl. 11. A. Drummondii. Trelease (2), 
101, 104, pl. 15. <A. floridanum. ‘Trelease (2), 102, 105, pl. 
16. A. Ginnala. Schneider, f. 220; Shirasawa, 279, pl. 12. 
A. glabrum. Trelease (2), 101, 102, pl. 14. A. grandidenta- 
tum. Trelease (2), 102, 104, pl. 16. A. japonicum. Shira- 
sawa, 276, pl. 11. A. leuwcoderme. Trelease (2), 105. A. 
macrophyllum. Schneider, f. 218; Trelease (2), 101, 103, pl. 
15. A. monspessulanum. Bosemann, 63; Schneider, f. 221. 
