28o The Ohio Naturalist. [Vol. V, No. 4, 



36. Climbing shrubs with axillary thorns, light gray bark and a prom- 

 inent central scar. LYCIUM. 



36. Erect shrubs with thorns at the ends of twigs or spurs. RHAMNUS. 



37. Terminal bud self-pruned; twigs some shade of black, brown, or 



reddish. PRUNUS. 

 37. Terminal bud present. 38. 



37. Most of the slender branches ending in thorns not showing a ter- 



minal bud or self-pruning scar; lateral thorns with one or two 

 large buds at the base. CYDONIA. 



38. Buds conical, pungent, pubescent, twigs glabrous or nearly so, 



mostly yellow-olive; trees with erect growth, the branches not 

 spreading as in most of the apples. PYRUvS. 



38. Buds downy or pubescent, twigs usually pubescent, if glabrous then 



dark reddish-brown; trees with rounded crowns and spreading 

 branches. MALUS. 



39. Base of the petiole remaining on the stem. RUBUS. 



39. Petiole separated close to the stem. 40. 



40. Bundle scars numerous; pith large; erect shrubs or trees. ARALIA. 



40. Bundle scars 3; low or slender shrubs. 41. 



41. Leaf scars very narrow, often a mere line extending half way or 



more around the stem, not decurrent. ROSA. 



41. Leaf scars rather broad, somewhat decurrent; older bark shreddy. 



RIBES. 



— 42 — 



42. Leaf scars quite regularlv 2-ranked, that is with the third scar over 



the first. 43. 



42. Leaf scars not 2-ranked. oH. 



43. Pith interruptedly diaphragmed. with cavities, small, greenish- 



white; bundle scars 3. CELTIS. 



43. Pith solid, or if with cavities then with a single bundle scar or with 



several scattered bundle scars. 44. 



44. Terminal bud elongated, naked, silky or tomentose. 45. 

 44. Terminal bud with numerous or several bud scales. 46. 



44. Terminal bud absent, the twigs showing a terminal self-pruning scar 



at the morphological tip. 49. 



45. Pith diaphragmed; buds dark silky; lateral buds rounded not 



stalked; leaf scars U-shaped; bundle scars 5-7, stipular scars 

 none; bark with fetid odor. ASIMINA. 



45. Pith not diaphragmed; buds light gray; lateral buds elongated, 



prominently stalked, tomentose; stipular scars prominent; leaf 

 scars not U-shaped. HAMAMELIS. 



46. With 10-20 visible scale leaves; stipular scars and medullary rays 



very prominent; leaf scar oblique, beside the axillary bud. 



FAGUS. 



46. Visible scales 3-8. 47. 



47. Bundle scars .several, scattered; pith more or less 5-angled; bark 



close with rough ridges; stipular scars present. CASTANE.\. 



47. Bundle scars 3. 48. 



48. Trunk and larger branches with jxqjery or leathery bark ; catkins 



in winter; leaf scar oval or semicircular. BETULA. 



48. Bark not papery or leatherv; no catkins; leaf scar narrow, con- 



tracted between the bundle scars. AMEL.\NCHIER. 



49. Visible bud scales 1-3. 50. 



49. Visible scales more than 3. 52. 



50. Bundle scar i ; visible scales 2; twigs brown, puljescent; pith some- 



times with cavities. DIOSPYROS. 

 50. Bundle scars sciittered, several. 51. 



