78 Spring Flora of Ohio. 



b. Flo'ccers in umbellate corymbs, appearing with the leaves. 



A'-cer sac-char'-um Marsh. {A. saccharinum Wang.) Sugar or Rock 

 Maple. — Bark gray; internodes mostly slender and elongated, com- 

 nionl}- glossy and reddish ; buds gray, conical, slender and acute ; no 

 stipules; leaves 5-lobed (a few 3-lobed) with narrow sinuses, 4-7 in. 

 broad, base truncate or slightly cordate with open sinus, light green 

 above, grayish below. 



A'-cer sac-char'-um bar-baMum (Mx.) Trel. Sugar or Rock Maple. — 



Bark gray to almost black; internodes often shorter and stouter, com- 

 monly dull but reddish ; buds gray pubescent or dark, conical ovoid, 

 often obtuse; no stipules; leaves o-lobed with open sinuses (lateral 

 lobes often with dilatations), usually about 4 in. broad, somewhat glossy 

 above, pale or glaucous (often downy) beneath. 



A'-cer ni'-grum Mx. f. {A. saccharinum var. nigrtcnt T. & G.) 

 Black Sugar-Maple. — Bark nearly black; internodes stout, sometimes 

 short, dull, buff; buds dark, ovoid, often obtuse; stipules adnate 

 triangular or oblong, foliaceous ; leaves o-5-lobed, usually 5-6 in. 

 broad, with drooping sides, often cordate with closed sinus, dull and 

 dark green above, clear green and usually downy below. 



b. Flo~Luers in umbel-like clusters, much preceding the leaves.) 



A'-cer sac-cha-ri'-num L. [A. dasycarpmn Ehrh.) White or Silver 

 Maple. — Leaves very deeply 5-lobed, with the sinuses rather acute, 

 silvery-white underneath, the divisions narrow, cut-lobed and toothed ; 

 petals none ; fruit woolly when young, with large divergent tPFt h . ivt^^ 



A'-cer ru'-brum L. Red or Swamp Maple. ^Leaves 3-5-lobed with 

 acute sinuses, whitish underneath, the lobes irregularly serrate and 

 notched; petals linear-oblong; fruit smooth, on prolonged, drooping 

 pedicels. 



A. Leaves pinnate ; leaflets .3-5. 



A'-cer ne-gun'-do L. [Negundo aceroides^lc£:VLc\\) Box Elder; Ash- 

 leaved Maple. — Flowers dioecious, petals none, sterile flowers on capil- 

 lary pedicels, the fertile in drooping racemes ; tree, the twigs light- 

 green. 



LI. Order HIP-PO-CAS-TAN-A'-CE->E. BUCKEYE FAMILY.— Flowers 



mostly unsymmetrical and irregular ; leaves opposite, exstipulate, 

 digitate. 



