ILLINOIS N>>TURAL HISTORY SURVEY MANUAL 1 



KEY TO FAMILIES 



1. Trees or shrubs, erect 2 



Shrubs (vines) that climb 17 



Herbs 19 



2. Bark and leaves spicy, aromatic. . . .LAUREL FAMILY p. 118 

 Bark and leaves not thus 3 



3. Flowers chocolate brown, 3-parted; fruits bananalike 



CUSTARD APPLE FAMILY p. 1 13 



Not thus 4 



4. Leaves palmately 5-9-foliate. ..SOAPBERRY FAMILY p. 190 

 Leaves pinnately divided; sap milky 



CASHEW FAMILY p. 184 



Not thus 5 



5. Flowers yellow, blooming in fall 



WITCH-HAZEL FAMILY p. 144 



Not thus 6 



6. Flowers 4-parted 7 



Flowers 5 or 6-parted 10 



Flowers in catkins, pendant or erect. . ..BIRCH FAMILY p. 73 



7. Leaves alternate, simple. .DOGWOOD FAMILY in part p. 225 

 Leaves alternate, compound, dotted with clear spots 



RUE FAMILY p. 178 



Leaves opposite 8 



8. Leaves 3-foliate BLADDER NUT FAMILY p. 189 



Leaves simple 9 



9. Flowers dull purple. ..STAFF TREE FAMILY in part p. 187 

 Flowers greenish, white or vellow, many in cluster 



DOGWOOD FAMILY in part p. 225 



10. Leaves opposite 11 



Leaves alternate 12 



11. Flowers greenish yellow, solitary or few in cluster 



STAFF TREE FAMILY in part p. 1 87 



Flowers white in dense clusters 



HONEYSUCKLE FAMILY in part p. 321 



12. Flowers very small or small in lateral clusters • • • 13 



Not thus 14 



13. Petals separate HOLLY FAMILY p. 186 



Petals more or less united. ..HEATH FAMILY in part p. 227 



14. Flowers irregular, butterfly shaped 



PULSE FAMILY in part p. 1 57 



Flowers regular 15 



15. Stamens very many; flowers conspicuous 



ROSE FAMILY p. 145 



Stamens nc3t more than 12 16 



16. Petals incurved BUCKTHORN FAMILY p. 192 



Petals not incurved; flowers white 



SAXIFRAGE FAMILY in part p. 139 



30 



