Feb., 1905.] Key— Ohio Woody Plants. 281 



51. Twigs grayish-brown or reddish, usually zigzag; bark mucilaginous, 

 fibrous; buds rather fleshy, usually bright red; medullary rays 

 prominent when the bark is removed; the winged fruiting 

 panicle often persistent. TILIA. 



51. Twigs glabrous or pubescent, reddish or vellowish-brown ; pith 

 5-angled. CASTA NE A. 



51. Twigs downy, gravish-green ; pith white, cylindrical, large; bark 

 very fibrous. BROUSSONETIA. 



51. Twigs coarsely glandular pubescent or sparingly hairy, brown; pith 



brown, cylindrical, small. CORYLUS. 



52. Bundle scars scattered; leaf scars oblique; twigs gray or light 



brownish-gray. MORUS. 



52. Bundle scars 3. 53. 



53. Twigs dark reddish-brown, speckled, often zigzag; buds reddish- 



violet, often superposed or clustered; leaf scars not oblique but 

 below the lateral bud. CERCIS. 



53. Twigs dark brown, not speckled; buds not superposed; leaf scars 



oblique. 54. 



54. Bark smooth, trunk and larger branches with peculiar fluted or 



projecting ridges; bud scales brown, finelv pubescent; staminate 

 catkins in the bud in winter. CARPINUS. 



54. Trunk not with fluted or projecting ridges. 55. 



55. Bark in rough ridges; no catkins; twigs and buds in most cases 



pubescent ; some species with characteristic transverse self- 

 pruning scars on the twigs, others with corky ridges. ULMUS. 

 55. Bark scaly, fine-furroAved, the ftirrows usually somewhat spiral; 

 bud scales green with brown tips, nearly glabrous; staminate 

 catkins exposed in winter. OSTRYA. 



55. Bark of trunk and larger branches separating into papery or leath- 



ery sheets; catkins in winter. BETULA. 



— 56 — 



56. With 2 or more superposed axillary buds ; all except 1 may be very 



small. 57. 



56. Axillary buds single or 2 or more side by side ; not superposed. 67. 



57. Pith diaphragmed, with air cavities, brown; twigs thick, with large 



leaf scars and 3 prominent bundle scars ; large trees. JUGLANS. 



57. Pith solid. 58. 



58. Stems twining ; leaf scars circular with numerous bundle scars ; buds 



partly hidden. MENISPERMUM. 



58. Stems not twdning. 59. 



59. Buds partly sunken, hardly projecting beyond the surface; terminal 



bud self-pruned or tips of branches withering. 60. 



59. Buds not sunken in the epidermis. 61. 



60. Leaf scar not surrounding the axillary buds; pith large, chocolate- 



colored; twigs robust, polished, mottled white and purplish- 

 brown. GYMNOCLADUS. 

 60. Leaf scar svirrounding the axillary buds, quadrangular- U-shapcd; 

 bark with pungent odor; pith white. PTELEA. 



60. Leaf scar covering the axillary buds; pith small; twigs brown, 



polished, often zigzag. GLEDITSIA. 



61. Pith cylindrical or nearly so. 62. 



61. Pith more or less 5-angled, yellowish or brownish; terminal bud 



large; bundle scars scattered; trees with tough twigs. HICORLl. 



62. Leaf scar surrounding the hairv axillarv buds; bundle scars 5-9; 



terminal bud self-pruned. CLADRASTIS. 



62. Leaf scar not surrounding the axillary buds. 63. 



63. Bark verv spicv-aromatic, fragrant; buds often stalked and clus- 



tered. ■ BENZOIN. 



