June, 1905.] Key to the Genera of Ohio Woody Plants. 
367 
42. Bark of trunk and larger branches separating into papery or 
leathery sheets; trees or shrubs with glabrous, pubescent, or 
glanduiar-warty twigs. Betula. 
42. Bark of trunk scaly, fine furrowed; twigs pubescent; carpellate 
catkin in fruit appearing like that of the hop. Ostrya. 
42. Bark of trunk and larger branches smooth or rough, not scaly and 
fine furrowed and not separating into papery or leathery sheets; 
twigs coarsely glandular pubescent or nearly glabrous; fruit a 
large nut in a leafy or partly coriaceous cup or involucre. 
Corylus. 
—4.3— 
43. Leaves 2-ranked. 44. 
43. Leaves not 2-ranked. 4.5. 
44. Bark of trunk and larger branches separating into papery or leath- 
ery sheets; leaves doubly serrate, the lateral veins ending in the 
main serrations, teeth or lobes. Betula. 
44. Bark not in papery or leathery sheets; leaves not doubly serrate, 
the lateral veins not ending directly in the serrations or teeth. 
Amelanchier. 
44. Bark not in papery or leathery sheets; leaves doubly serrate ending 
in the main serrations or lobes. Corylus. 
45. Leaves with spine-tipped teeth or lobes, or some of the leaves 
reduced to simple or branched spines. 40. 
45. Leaves not with spines. 47. 
46. Leaves evergreen, with spine-tipped lobes; trees. Ilex. 
46. Leaves reduced to simple or branched spines, some leaves without 
spines and deciduous each year; shrubs. Berberis. 
47. Pith solid but with prominent diaphragms, cylindrical; vascular 
bundles 3 in the base of the petiole; trees. Nyssa. 
47. Pith not both diaphragmed and solid. 48. 
48. Leaves with 1 or more disc-like, wart-like, or tooth-like glands on 
the petiole or at the base of the blade, or with tooth-like glands on 
top of the midrib. 49. 
48. Leaves not with distinct glands on the top of the petiole or midrib, 
or at the base of the blade, but they may be glandular-hairy or 
glandular-dotted. 53. 
49. Pith 5-angled, leaves usually more or less deltoid with gland-tipped 
teeth. Populus. 
49. Pith cylindrical or nearly so. 50. 
50. With typical lateral thorns. Crataegus. 
50. Not with typical lateral thorns, but some may have thorn-like 
stunted branches. 51. 
51. With tooth-like glands along the top of the midrib; shrubs. Aronia. 
51. Glands tooth-like, mostly at the base of the midrib; leaves glabrous 
when mature, with long petioles; fruit a pome. Pyrus. 
51. Glands only on the petiole or near the base of the blade. 52. 
52. Glands tooth-like or rounded, or the leaf with gland-tipped teeth, 
but not with 2-4 large disc-like glands at the base on the edges 
of the blade; terminal bud absent when the twig is mature; 
twigs with brittle zones; fruit a capsule, in catkins. Salix. 
52. Twigs green, red, or red and green; nectar glands disc-like, usually 
2-4 near the base at the edge of the blade; terminal bud present; 
twigs without Ijrittle zones; fruit a velvety drupe. Amygdalus. 
52. Glands various; twigs not red and green, some with cleavage planes 
in basal joints but not with brittle zones; terminal bud present 
or absent, fruit a smooth drupe. Prunus. 
