June, 1905.] Key to the Genera of Ohio Woody Plants. 
365 
12. Leaves serrate, dentate, crenate, pinnatifid, or variously lobed. 31. 
13. With stipular rings at each leaf node ; leaves large. Magnolia. 
13. Base of petiole covering the axillary bud and twigs with peculiar 
rings but not at the leaf nodes. Dirca. 
13. Not with stipular rings; base of petiole not covering the axillary 
bud. 14. 
14. Leaves evergreen, some on wood of the previous season. 15. 
14. No leaves on wood of the previous season. 18. 
15. Leaves glabrous; erect shrubs or small trees. 16. 
15. Leaves hirsute or pubescent; low trailing or spreading shrubs. 17. 
16. Leaves green on both sides, thick, coriaceous, oblong to oblance- 
olate, 5—10 in. long; winter buds very scaly. Rhododendron. 
16. Leaves green on both sides, or glaucous beneath, coriaceous, 2—5 in. 
long; oval or oval-lanceolate, winter buds naked. Kalmia. 
17. Leaves oval or nearly orbicular, hirsute beneath; twigs hirsute; 
prostrate shrubs. Epigaea. 
17. Leaves spatulate, minutely pubescent, with hairs on the margins; 
trailing or spreading shrubs. Arctostaphylos. 
18. With thorns; either small trees with milky sap or low vine-like 
shrubs. 19. 
18. Without thorns. 20. 
19. Trees or erect shrubs with prominent thorns; leaves with milky sap, 
the base obtuse, truncate, or cordate. Toxylon. 
19. Climbing shrubs with axillary thorns; leaves not milk}', narrowed 
into short petioles. Lycium. 
20. Pith -wnth prominent diaphragms but solid; vascular bundles in 
base of petiole 3—7. 21. 
20. Pith not diaphragrned but sometimes with cavities. 22. 
2 1 . Leaves 2-ranked ; bark with fetid odor ; vascular bundles in base of 
petiole 5—7. Asimina. 
21. Leaves not 2-ranked; vascular bundles in base of petiole 3. Nyssa. 
22. Leaves resin-dotted, waxy-dotted or punctate. 23. 
22. Leaves not dotted or punctate. 24. 
23. Shrubs or small trees; leaves oblong-lanceolate, spatulate, or 
oblanceolate, short pointed, narrowed at the base. Myrica. 
23. Shnibs wth obovate or elliptic leaves narrowed at the base; bark 
spicy aromatic; axillary buds superposed. Benzoin. 
23. Low shrubs; leaves ovate-lanceolate, wedge-shaped at the tip. 
Gaylussacia. 
24. Pith prominently 5-angled; leaves with deciduous stipules and with 
bristle tips; trees. Quercus. 
24. Pith cylindrical or nearly so; leaves downy with prominent 
deciduous stipules. Cydonia. 
24. Pith cylindrical or nearly so; no stipules or stipular scars, if with 
minute stipules then glabrous. 25. 
25. Leaves with the upper 2 lateral veins more or less parallel with the 
midrib. Cornus. 
25. Leaves pinnately veined to the tip. 26. 
26. Bark when cut very resinous, fragrant; pith large, usually brown. 
Cotinus. 
26. Bark not resinous. 27. 
27. Trees, sometimes with cavities in the pith; leaves oval or ovate, 
acute or acuminate, the petioles loosely jointed with the twigs. 
Diospy’-os. 
2”. Pith not with cavities; shrubs. 28. 
28. Leaves with long petioles; twigs not clustered and the leaf inter- 
nodes rather uniform, with minute stipules, llicioides. 
