104 ROSACEAE 



1. PL AT ANUS L. 



Characters of the family. 



1. P. occidentalis L. SYCAMORE. Often 130 high : bark exfoli- 

 ating : leaves 4 / -9 / wide, truncate at base and lobed above : fruiting 

 heads long-peduncled. Common along streams. May. 



FAMILY 58. ROSACEAE B. Juss. 



Plants with alternate usually stipulate leaves, and irregular usually 

 perfect flowers. Calyx usually 5-lobed, and distinct from or adnate to 

 the ovary. Petals usually five. Stamens numerous. Carpels 1-many, 

 distinct or united. Fruit usually 1 -celled, and ovules 1-several. 



Woody plants. 

 Stems prickly. 



Petals pinkish. 9. ROSA. 



Petals white. 3. RUBUS. 



Stems not prickly. 



Flowers in corymbs. 1. OPULASTEE. 



Flowers in panicles. 2. SPIRAEA. 



Herbs. 



Ovary superior. 



Styles persistent on the fruit. 7. GEUM. 



Styles not persistent. 



Flowers pure white. 4. FRAGARIA. 



Flowers yellowish. 



Receptacle enlarged in fruit. 5. DUCHESNEA. 



Receptacle not enlarged in fruit. 6. POTENTILLA. 



Ovary inferior. 8. AGRIMONIA. 



1. OPULASTBR Medic. 



Calyx 5-cleft. Petals 5, white. Stamens 20-40. Follicles 1-5, in- 

 flated, 2-valved, 2-4-seeded. 



1. O. intennedius Rydb. NINE-BARK. 3-10 high, branching : 

 leaves orbicular, serrate, 3-lobed above, petioled : ovaries 2-4, finely 

 pubescent. Rocky bluffs of the Missouri River from Rock Creek to 

 Courtney. Frequent. May. 



2. SPIRAEA L. 



Like the last but follicles 5-8, 2-many-seeded, not inflated and de- 

 hiscent by but one suture. 



1. S. salicifolia L. MEADOW SWEET. 2-3 high : leaves petioled, 

 oblanceolate, serrate : flowers small, white, in dense terminal panicles. 

 In low meadows near Lake City fide Rev. Cameron Mann. Very rare. 

 July-September. 



3. RUBUS L. 



Shrubs with prickly stems, terminal panicled flowers and alternate com- 

 pound leaves. Calyx 5-parted. Petals 5. Stamens numerous. Carpels 

 many, ripening into drupelets imbedded in the succulent receptacle. 



Leaflets white beneath. 1. B. occidentalis. 



Leaflets not white beneath. 



