ACER 



ACER 



203 



ti;ir habit. Var. globosum, Rehd. Dwarf, compact: 



Ivs. glaucous beneath: Hs. bright scarlet. Var. Drum- 



moiidii, Sarg. (.1. Drummniidii, Hoolv. & Arn.) Lvs. 



largo, mostly 3-lobed, tomentosc beneath: fr. bright 



scarlet. Southern states. S.S. 2:95. Var. tomentosum, 



Kirchn. (.1. lonientbsum, Desf. A.ruhrum var. fulgeiis, 



Ilort.). Of moderate growth: lvs. 5- 



lobed, pubescent beneath: fls. bright 



red. Var. tridens, Wood (.4. micro- 



phf/Uiim, Pax, A . seiiiiorbicutatum, Pax) . 



Lvs. 3-lobed, rather small, rounded or 



rarely cuncate at the base, usually 



pubescent below. On .young plants and 



vigorous shoots, the lvs. are like those 



of the type. S.S. 13:626. Var. magni- 



ficum, Schwerin. Fall-coloring of the 



lvs. scarlet with green veins. M.D. 



1910:1. — The form distributed as var. 



Schlesingeri, Schwerin, does not differ 



from the type. 



Section Saccharina. 



38. saccharum, Marsh. (A. sacchdri- 

 num, Wang., not Linn? A. barbatutn, 

 Michx.). Sugar or Rock Maple. Fig. 

 98. Large tree, 120 ft., withgr^- bark: 



lvs. 3-5-lobed, cordateTS^Cin. long, with narrow and 

 deep sinuses; lobes acuminate, sparingly dentate, usu- 

 ally glaucous and glabrous beneath: corymb hairy: fr. 

 with slightlv spreading wings, glabrous. E. N. Amer. 

 S.S. 2:90. Em. 558. H.T. 324. Gn. 65, p. 55 (habit). 

 — .\n excellent street and shade tree of upright, dense 

 growth, turning bright yellow and scarlet in autumn. 

 It does well in almost every soil. ,Var. Rugelii, ReRd. 

 (.1. Rugelii, Pax, A. saccharum var. barbatum, Trel.). 

 Lvs. 3-lobed, generally broader than^ong, 2-5 in. 

 across, pale green or glaucous beneath, and at length 

 mostly glabrous, coriaceous ; lobejjiearh' entire. Central 

 states. S.S. 2:91 {as var. nigrum). Var. monumentale, 

 Schwerin (.4. Jitgrum var. moni imenlale, Rehd.). Of 

 upright, columnar habit. ' 



39. floridanum, Chapm. (A. barbatum var. florida- 

 luim, Sarg.). Tree, rarely 50 ft., with pale bark: lvs. 

 mostly truncate at the base, 3-lobed, 1 } 2-3 in. across, 

 glaucous beneath, pubescent; lobes obtuse, entire or 

 slightly 3-lobed: corymb sparingly hairy or nearly gla- 

 brous: fr. sparingly villous, finally glabrous. Gulf 

 states. S.S, 2:91. G.F. 4:148. 



4Q. Qigrum, Michx. (.4. sacchdx^num var. nigrum, 

 Torr. i.\? Gra}'. ^1. saccharum var. nigrum, Brit.). 

 Black Maple. Fig. 99. Large tree, 120 ft., with black 

 bark: lvs. cordate, with the sinus mostly closed, gener- 

 ally 3-lobed, .5-6 in. across, with broad sinuses, the 

 sides of the blade mostly drooping, green and pubes- 

 cent beneath; lobes acute, entire or obtusely toothed: 

 fr. with diverging wings. Central states. S.S. 13:625. 

 fl.T. 326. — Similar to A. saccharum, but of duUer 

 appearance and less dense habit 



41. leucoderme, Small {A. sdccharum var. leuco- 

 derme, Sarg.). Tree, to 25, rarely to 40 ft., with hght 

 gray or grayish brown bark: lvs. 3-5-lobed, 2-3M in. 

 across, truncate or sUghtly cordate at the base, bright 

 yellow-green and soft-pubescent beneath; lobes acu- 

 minate, sinuately dentate: corymbs glabrous: fr. vil- 



90, Acer nigrum. — Black Sugar Maple. fX?-J 



98. Acer saccharum. — Common Sugar Maple. (X J^2) 



lous, finally glabrous; wings wide-spreading. From N. 

 C. to Ga. and La. S.S. 13:624. — Sometimes planted as 

 a street tree in Ga. and Ala.; hardy at the Arnold 

 Arboretum. 



42. grandidentatum, Nutt. Tree, 40 ft., with dark 

 brown baric: petioles comparatively short: lvs. 

 slightly cordate, 3-5-lobed, with broad sinuses, 2-3 in. 

 across, pubescent beneath, coriaceous; lobes acute or 

 obtuse, entire or slightly 3-lobed: corymbs few-fid., 

 hairy, short-stalked. Rocky Mts. S.S. 2:92.— Hardy 

 at the Arnold Arboretum. 



43. diabolicum, Koch. Tree, to 30 ft: branchlets 

 pubescent: lvs. 5-lobed, cordate or subcordate, 4-6 

 in. across, pale green beneath and sparingly pubescent; 

 lobes broadly ovate-acuminate, coarsely and remotely 

 dentate with acute or obtusish teeth: fls. from lateral 

 leafless buds; staminate on long and pendulous, hairy 

 pedicels; sepals wholly or partly connate, petals want- 

 ing; pistillate in few-fid. racemes; sepals and petals dis- 

 tinct: pecUcels of the fr. J2-2 in. long; nutlets thick, 

 strongly veined, bristly; wings upright or slightly 

 spreading. Japan. G.C! IL 15:5.32. S.T.S. 1:67. Var. 

 purpurascens, Rehd. (A. purpurdscens, Franch. & Sav. 

 A. pulchrum, Lavall6). Fls. purple: lvs. turning red in 

 autumn. S.LF. 1:65. — Hardy at the Arnold Arboretum ; 

 similar to A. pseudoplatanus, but lvs. larger; the var. 

 purpurascens is to be recommended for its early-appear- 

 ing purple fls. 



Section Trifoliata. 



44. nikoense, Maxim. Fig. 100. Tree, 40 ft.; branch- 

 lets pubescent: Ifts. ovate or oblong-elliptic, short- 

 stalked, acute, entire or obtusely den- 

 tate, 2-5 in. long, viUous-pubescent 

 beneath, petioles hairy, J^-13^ in. 

 long: corymb few-fld., pubescent: fr. on 

 nodding pedicels 's-K'in, long; nutlets 

 thick, hairy; wings upright, curved 

 inward. Japan, Cent. China. G.F. 

 6:155 (adapted in Fig. 100.) Gt. 41, p. 

 149. S.LF. 1:68. J.H.S. 29:81. R.H. 

 1912:126, 127.— Very distinct; lvs. 

 turning brilliant scarlet in autumn. 



45. griseum, Pax (A. nikoense var. 

 griseum, Franch.). Tree, to 25 ft., with 

 cinnamon-brown bark separating in 

 thin flakes: branchlets pubescent: Ifts. 

 short-stalked, elUptic or ovate-oblong, 

 1 -2 in . long, acute, coarsely toot hed with 

 large bluntish teeth, the lateral ones 



