198 



ACER 



ACER 



D. Ovary and young fr. tomentose: 

 short-stalked: fas. deeply 5- 



lobed 36. saccharinum 



DD. Ovary and young fr. glabrous: 

 fls. on long pedicels: fas. 3-5- 



lobed ' 37. rubrum 



BB. Sepals connate and petals wanting at 

 least in the staminate fls.; fls. on 

 long, pendulous, mostly hairy pedi- 

 cels. 



c. Pistillate and staminate fls. corym- 

 bose, terminal and lateral: fr. 

 glabrous or villous. American 

 species. 



D. Corymb sessile or nearly sessile. 

 E. Lvs. glaucous or pale beneath. 

 F. Lobes acuminate; Ivs. gla- 

 brous beneath at maturity. 38. saccharum 

 FF. Lobes obtuse; Ivs. pubescent 



beneath 39. floridanum 



KK. Lvs. green beneath; lobes acu- 

 minate. 



F. Bark of trunk dark: Ivs. hir- 

 sute-pubescent, 5-6 in. 



across 40. nigrum 



FF. Bark pale: Ivs. soft-pubescent 



beneath, S-S% in. across. .41. leucoderme 

 DD. Corymbs short-stalked: fas. pu- 

 bescent beneath; lobes obtuse or 



acute 42. grandi- 



cc. Pistillate fls. racemose, with petals [dentatum 



and distinct sepals, staminate 

 corymbose, with connate sepals and 

 without petals, both from lateral 

 leafless buds. Japanese species. . .43. diabolicura 

 AA. Lvs. S-S-foliolate: fls. di&cious. 



B. Fls. in terminal corymbs, after the fas.: 



winter-buds with several imbricate 



scales: disk large, annular: fas. 3- 



foliolate. 



c. Petioles, Ivs. beneath and corymbs 



pilose; petioles short. 

 D. Shape of Ivs. elliptic-oblong, spar- 

 ingly serrate, H-5 in. long . . . .44. nikoense 

 DD. Shape of Ivs. elliptic, coarsely 



dentate, 1-2 in. long 45. griseum 



cc. Petioles, fas. and corymbs glabrous; 

 fas. oblong -lanceolate; petioles 



slender 46. mandshuri- 



BB. Fls., at least the pistillate, in lateral, [cum 



long and slender racemes: winter- 

 buds with 2 valvate scales. 

 c. Petals present; fls. of both sexes in 

 racemes, sometimes leafy at base, 



with the Ivs.: Ivs. S-foliolate 



D. Petioles and fas. pubescent be- 

 neath: sepals and petals 5 47. Henryi 



DD. Petioles and Ivs. glabrous at 



maturity: sepals and petals 4. .48. cissifolium 

 cc. Petals wanting; pistillate fls. in 

 pendulous racemes, staminate co- 

 rymbose, pendulous, both sexes 

 from lateral leafless buds before 

 the Ivs.: hs. 3-S-foliolate 49. Negundo 



Section CAMPESTRIA. 



1. monspessulanum, Linn. (A. Irilob&tum, Lam.). 

 Shrub or small tree, 25 ft. : Ivs. 3-lobed, coriaceous, 1-3 

 in. across, shining above, glaucous and glabrous be- 

 neath; lobes entire or with few obtuse teeth: corymbs 

 erect: fr. with slightly spreading wings. S. Eu., N. 

 Afr., W. Asia. Gt. 1893, p. 363. H.W. 3, p. 46. G.W. 8, 

 p. 195 (habit). Shrub or small tree of slow growth, with 

 a dense, rounded head and, in temperate regions, nearly 

 evergreen foliage, thriving well in dry situations. Var. 

 ibericum, Koch. (A. ibericum, Bieb.). Lvs. larger, the 

 inner lobes usually slightly 3-lobed, obtuse. 



2. campestre, Linn. Shrub or tree, occasionally 50 

 ft., with corky branches: Ivs. 3-5-Iobed, IVr^A in. 

 long, green and pubescent beneath or nearly glabrous; 

 lobes entire or the middle one slightly 3-lobod: 

 corymbs erect, hairy: fr. with horizontally spreading 

 wings. Eu., W.Asia. H.W.3:46, p. 45. F.E. 20, pi. 108 



(habit). Gt. 1893, p. 327. Shrub or tree of moderate, 

 dense growth, with dull green foliage, valuable for 

 planting as undergrowth and on dry ground. Many 

 varieties and garden forms: Var. argenteo-variegatum, 

 Schwerin. Lvs. with large white blotches. Var. pul- 

 verulentum, Kirchn. Lvs. sprinkled with white. Var. 

 austriacum, DC. Usually a tree: Ivs. 5-lobed, with 

 acute, nearly entire lobes: fr. glabrous. F.E. 19, pi. 98 

 (habit). Var. tauricum, Kirchn. Shrub: Ivs. 5-lobed; 

 small, lobes 3-lobed. Var. hebecarpum, DC. Fr. and 

 generally the Ivs. pubescent beneath. 



3. <5palus, Mill. (A. Italum, Lauth). Small tree, 30 

 ft. : Ivs. 5-lobed, 3-5 in. long, glaucous beneath and at 

 length glabrous; lobes obtusely dentate, short and 

 broad, the middle ones often 3-lobed: corymbs some- 

 what drooping: fr. with slightly spreading wings. S. 

 Eu., Orient. W.D.B. 2:171. A variable species, simi- 

 lar to a small-lvd. sycamore maple. Var. hyrcanum, 

 Pa.x(A.hyrcanum, Fisch.&Mey. A. tauricum, Hort. A. 

 trilobdlum, Hort., not Lam.). Petioles very slender, red, 

 2-4 in. long; segms. of the Ivs. 3-lobed, longer than 

 broad, with straight margins. Gt. 1893, p. 361. 



91. Acer Miyabei. 



CXH) 



Section PLATANOIDEA. 



4. Miyabei, Maxim. Fig. 91. Tree, to 40 ft.: 

 branches corky: Ivs. 5-lobed, lobes lobulate or coarsely 

 dentate, obtusely acuminate, with obtuse teeth, at first 

 pubescent on both sides, later only beneath, pale green 

 beneath, 5-6 in. long: corymbs long-stalked, 10-15-fld.. 

 pubescent: fr. pubescent with horizontally spreading 

 wings. Japan. G.F. 6:143 (adapted in Fig. 91). S.I.F. 

 2:45. Handsome, vigorous tree, quite hardy at the 

 Arnold Arboretum. 



5. platanoides, Linn. NORWAY MAPLE. Fig. 92. 

 Large tree, to 100 ft.: Ivs. 5-lobed, cordate at base, 

 glabrous, light green and lustrous beneath, lobes 

 pointed, remotely dentate with pointed teeth: corymbs 

 glabrous; fls. yellowish green: fr. glabrous, with hori- 

 zontally spreading wings. Eu., Caucasus. H.W. 3:45. 

 Pax 49. Gt. 42, p. 561, 584, 585. Large, handsome tree, 

 with round, spreading head, resembling somewhat A. 

 saccharum. The Ivs. turn pale yellow in autumn. Many 

 garden forms, some of which are here arranged in two 

 groups, the first being remarkable for the manner in 

 which the Ivs. are cut and for the habit; the second 

 being chiefly remarkable for their coloring: 



(1) Var. cucullatum, Nichols. Lvs. irregularly and 

 shortly lobed, crimped, light green. Var. dissectum, 



