Jones: Flora of Illinois 31 



27. Bark smooth; ovary superior; corolla and 



calyx 4-lobed; stamens 2: flowers small, 

 white, regular, in terminal panicles; 

 fruit a 2-loculcd, 1-2-seedcd, black, 



berry-like drupe 



Ligustrum in 98. Oleaceae 



26. Leaves with petioles usually 1 cm or more in 

 length; calyx and corolla each 4-lobed; 

 stamens 4. 



28. Leaves glabrous, or sparsely pubescent 



along the midvein, at least the upper 

 ones usually in whorls of three; flowers 



in globose heads 



Cephalanthus in 119. Rubiaceae 



28. Leaves pubescent, at least on the lower 

 surface, never whorled; flowers in cymes 



90. CORNACEAE 



Section 13. Trees or Shrubs With Alternate, Compound Leaves 



1. Leaves once compound, i.e., not decompound. 

 2. Leaflets 3. 



3. Prickles present. 



4. Flowers rose; carpels enclosed in a hypanthium ("hip") which be- 

 comes red and succulent in fruit; achenes bony 



Rosa in 53. Rosaceae 



4. Flowers white; fruit of several or many fleshy drupelets inserted on a 



convex receptacle Rubus in 53. Rosaceae 



3. Prickles none. 



5. Leaflets silky-pubescent; stipules present; flowers yellow, perfect; 



achenes densely pubescent Potentilla in 53. Rosaceae 



5. Leaflets not silky-pubescent, either glabrous or only short-pubescent; 

 stipules absent; flowers greenish; plants polygamous or dioecious. 

 6. Leaflets sessile, pellucid-punctate; fruit a suborbicular samara, 



1.5-3 cm in diameter Ptelea in 34. Rutaceae 



6. Leaflets, at least the terminal one, petiolulate; fruit a drupe 



49. Anacardiaceae 



2. Leaflets more than 3. 



7. Leaves palmately compound. 



8. Stems prickly; tendrils none; stamens numerous 



Rubus in 53. Rosaceae 



8. Stems not prickly; tendrils present; stamens 5. 

 7. Leaves pinnately compound. 



9. Leaflets entire or undulate, or remotely denticulate. 



10. Leaflets 3-7, silky-pubescent, revolute-margined; flowers yellow; 



fruit an achene; shrub 30-100 cm tall 



Potentilla in 53. Rosaceae 



10. Leaflets 5-51. 



11. Leaflets with pellucid dots; flowers greenish yellow in small 

 axillary cymes, appearing before the leaves; branches often 

 with sharp stout stipular prickles; fruit ellipsoid, 4-6 nmi 



long, 1-seeded, spicy flavored 



Zanthoxylum in 34. Rutaceae 



11. Leaflets without pellucid dots. 



