GENUS i. ROSE FAMILY. 243 



** Carpels opposite the sepals; stipules persistent (SORBARIEAE). 



Petals obovate or spatulate, imbricated ; leaves pinnate. 4. Schizonotus 



Petals strap-shaped, convolute in the bud ; leaves trifoliolate. $. Porter ant hit's. 



B. Fruit indehiscent, of achenes or drupelets. 

 * Carpels not enclosed in the fleshy calyx-tube (hypanthium). 

 i. Fruit of dry achenes, 



Ovaries 2-ovuled (ULMARIEAE). 6- Filipendula. 



Ovaries i-ovuled. 



Seed pendulous or ascending, borne in the ovary opposite to the base of the style. 



Style articulated with the ovary; calyx-tube from campanulate to nearly flat (POTENTILLEAE). 

 Style terminal or nearly so ; ovule and seed pendulous. 7. Potentilla. 



Style lateral ; ovule and seed ascending. 

 Herbs ; achenes glabrous. 



Achenes numerous ; stamens about 20. 

 Leaves odd-pinnate. 



Receptacle" not enlarged in fruit ; petals yellow, obtuse or retuse. 



8. Argentina. 

 Receptacle somewhat enlarged in fruit, spongy ; petals red, acute or acuminate. 



9. Comarum. 

 Leaves 3-foliolate ; receptacle much enlarged in fruit. 



Receptacle not pulpy; petals yellow. 10. Ditchesnea. 



Receptacle very pulpy ; petals white or pinkish. ir. Fragaria. 



Achenes 10-15 ; stamens 5; leaves 3-foliolate. 12. Sibbaldia. 



Shrubs ; achenes hairy. 



Style filiform ; leaves 3-foliolate. I3 . Sibbaldiopsis. 



Style club-shaped ; leaves pinnate. I4 . Dasiphora. 



Style nearly basal ; ovule and seed ascending. 



Stamens numerous; flowers bracteolate Cleaves pinnate. 15. Drymocallis. 



Stamens 5 ; flowers ebracteolate ; leaves 2-3-ternately compound. 16. Chamaerhodos. 

 Style not articulated with the ovary ; calyx-tube urn-shaped or cup-shaped, contracted at the 



throat or mouth. 

 Style nearly basal ; inflorescence cymose ; petals none (ALCHEMILLEAE). 



Perennial herbs ; stamens 4, alternate with the sepals. 17. Alchemilla. 



Small annual herbs ; stamen i, opposite a sepal, rarely 2-5. - 18. Aphanes. 



Style terminal ; inflorescence spicate, racemose or capitate (SANGUISORBEAE). 

 Calyx-tube not prickly ; petals none. 

 Stamens 2-4, not declined ; pistil i. 



Perennial herbs ; stigma papillose ; leaflets toothed. 19. Sanguisorba. 



Annual or biennial herbs ; stigma brush-like ; leaflets pectinate-pinnatifid. 



20. Poteridium. 



Stamens of staminate flowers numerous, declined; pistils 2. 21. Poterium. 

 Calyx-tube and fruit prickly ; petals present, yellow. 22. Agrimonia. 



Seed erect, basal. 



Style wholly deciduous (COLURIEAE). 23. Waldsteinia. 



Style persistent in whole or in part. 



Calyx-tube hemispheric to turbinate, persistent; herbs (DRYADEAE). 

 Calyx-lobes and petals 5 ; leaves pinnate. 



Styles jointed, the upper part deciduous. 24. Geum. 



Styles not jointed, wholly persistent, mostly plumose. 25. Sieversia. 



Calyx-lobes and petals 8 or 9 ; leaves simple ; styles plumose. 26. Dryas. 



Calyx-tube salver-shaped, the limb deciduous ; the tube persistent, investing the achene ; 

 shrubs or trees (CERCOCARPEAE). 27. Cercocarpns. 



2. Fruit of fleshy or -nearly dry drupelets; ovary 2-ovulcd (RUBEAE). 



Drupelets very pulpy. 28. Rubits. 



Drupelets nearly dry, enclosed by the calyx. 29. Dalibarda. 



** Carpels enclosed in the fleshy calyx-tube (ROSEAE). 30. Rosa. 



i. OPULASTER Medic. Pfl. Anat. 2: 109. 1799. 



[PHYSOCARPA Raf. New Fl. N. A. 3: 73. 1836.] 

 [PHYSOCARPUS Maxim. Acta Hort. Petrop. 6: 219. 1879.] 



Branching shrubs, with petioled simple palmately lobed leaves, and white flowers in ter- 

 minal corymbs. Calyx campannlate, 5-lobed. Petals 5, rounded, inserted in the throat of 

 the calyx. Stamens 20-40, inserted with the petals. Pistils 1-5, short-stipitate, when 5 alter- 

 nate with the calyx-lobes. Stigma terminal, capitate. Pods 1-5, inflated, in our species at 

 length dehiscent along both sutures, 2-4-seeded. Seeds ovoid or globose, crustaceous, shin- 

 ing; endosperm copious. [Greek, resembling Opulus, the cranberry-tree.] 



Species about 12, of North America, and i in Mantchuria. Type species: Spiraea opulifolia L. 

 Follicles glabrous, shining. i- O. opulifolius. 



Follicles stellate-pubescent. 2. O. intermedius. 



