KEY TO GENERA 19 



47. Lenticels very conspicuous. . . Sambucus, p. 195 



47. Lenticels not conspicuous. . . Hydrangea, p. 99 



48. Leaf-scars linear, straight or curved. 49 



48. Leaf-scars not as above. 61 



49. Leaf-scars horseshoe-shaped. . . Calycanthus ,p. 97 



49. Leaf-scars straight or curved, but not horseshoe-shaped. 50 



50. Bud-scale one. 51 



50. Bud-scales two or more or none. 52 



51. Buds gummy within. . . Viburnum , p. 191 



51. Buds not gummy within. . . Salix ,p.46 



52. Bud-scales none (the young foliage naked, rusty- 

 brown). . .Viburnum, p. 191 



52. Buds with two or more scales. 53 



53. Bud-scales two, valvate. 54 



53. Bud -scales more than two. 58 



54. Youngest growth gray, or grayish-brown, not hairy. 55 



54. Youngest growth often highly colored (red, green, 

 purple, etc. ). 57 



55. Leaf-buds long, slender, tapering, lead-colored. . . Viburnum, p. 191 



55. Leaf-buds not long and slender. 56 



56. Buds dark red or rusty-brown, scurfy. . . Viburnum , p. 191 



56. Buds gray or brown, not scurfy. . . Cornus , p. 158 



57. Leaf-scars V-shaped, not raised, nearly meeting. . . Acer , p. 139 



57. Leaf-scars U-shaped, somewhat raised, connected 

 on each side by a narrow line. . . Cornus , p. 158 



58. Buds sessile. 59 

 58. Buds stalked. 60 



/^59. Branches short, numerous, rigidly spreading. . . Viburnum , p. 191- 



■59. Not as above. . . Acer , p. 139 



0. Leaf-scars meeting in a point. . . Acer , p. 139 



60. Leaf-scars not meeting. . . Viburnum, p. 191 



61. Leaf-scars very small and inconspicuous ; pith often 

 more or less excavated. . . Lonicera , p. 187 



61. Leaf-scars larger, pith continuous. 62 



62. Buds covered. 63 

 62. Buds not covered. 64 



