KOSACEAE. 491 



Pistils opposite the calyx-lobes ; petals white. 



Follicles united at the base ; petals obova }r oblong ; leaves pinnate. 



4. Sorbaria. 

 Follicles free; petals strap-shaped ; leaves trifoliolate. 



5. Portcranthus. 

 Pistils numerous or rarely few, ripening into i-2-seeded drupelets or achenes. 



Pistils ripening into drupelets crowded on the receptacle. 



Drupelets very pulpy. 6. Rubus. 



Drupelets nearly dry, enclosed by the calyx. 7. Dalibarda. 



Pistils ripening into achenes. 

 Style deciduous. 



Style nearly basal ; ovules ascending or nearly erect, orthotropous ; 



leaves pinnate. 8. Drymocallis. 



Style lateral; ovules ascending and amphitropous. 

 Achenes hairy ; low shrubs. 



Leaves pinnate ; style club-shaped ; flowers yellow. 



9. DasipJiora. 

 Leaves trifoliolate ; style filiform; flowers white. 



10. Sibbaldiopsis. 

 Achenes glabrous ; herbs. 



Achenes 10-15; stamens 5; leaves trifoliolate. 



11. Sibbaldia. 

 Achenes numerous; stamens about 20. 



Receptacle much enlarged and red in fruit ; leaves trifolio- 

 late. 



Receptacle pulpy, edible; petals white. 



12. Fragaria. 

 Receptacle not pulpy ; petals yellow. 



13. Duchesnea. 

 Receptacle in fruit some\\hat enlarged, spongy ; leaves 



pinnate; petals red. 14. Comarum. 



Receptacle not enlarged in fruit; leaves interruptedly pin- 

 nate ; petals yellow. 15. Argentina. 

 Style terminal or nearly so. 



Pistils numerous; ovules pendulous and anatropous. 



16. Potentilla. 



Pistils 2-6; ovules basal, erect. 17. Waldsteinia. 



Style persistent on the achene. 

 Pistils numerous; herbs. 



Calyx-lobes and petals 5; leaves interruptedly pinnate. 

 Style jointed above, the upper portion deciduous. 



1 8. Geum. 



Style not jointed. 19. Steversia. 



Calyx lobes and petals 8 or 9; leaves simple; styles plumose 



20. Dryas. 

 Pistil solitary; achene with a long plumose style; shrubs. 



21. Cercocarpus. 

 Pistils 5-15; fruit resembling a follicle, but indehiscent and i-seeded ; 



style not plumose; herbs. 22. Ulmaria, 



2. Fruit, 1-4 achenes, enclosed in the persistent dry receptacle; herbs. 



Calyx with 4 or 5 bractlets; petals none. 23. Alch'emilla. 



Calyx not bracteolate. 



Calyx bearing hooked prickles; petals 5. 24. A^rimonia. 



Calyx not prickly; petals none. 25. Sanguisorba. 



3. Fruit, numerous achenes, enclosed in the fleshy receptacle; shrubs with pinnate 



leaves. 26. Rosa. 



i. OPULASTER Medic. 



Branching shrubs, with petioled simple palmately lobed leaves, and white flow- 

 ers in terminal corymbs. Calyx campanulate, 5. lobed. Petals 5, rounded, in- 

 serted in the throat of the calyx, Stamens 20-40, inserted with the petals. Pistils 

 1-5, short-stipitate, when 5 alternate with the calyx-lobes. Stigma terminal, capi- 

 tate. Pods 1-5, inflated, 2-4-seeded. Seeds ovoid or globose, crustaceous, shin- 

 ing; endosperm copious. [Greek, a wild Opulus, or cranberry-tree.] Species 

 about 8, 3 of eastern N. Am., 4 of the Rocky Mts. and Pacific Coast, I in Mant- 

 churia. 



Follicles mostly 5, glabrous. I. O. opnlffolius. 



Follicles 2-4, finely pubescent. 2. O. intermedius. 



