172 FLORA OF PHILADELPHIA. 



Family 1 11. ROSACEAB B. Juss. Rose Family: 



. .. . ;, v> . A .<. 



Fruit not enclosed in a hollow receptacle, the so-called calyx. 



Pistils few, seldom more than 5, ripening into 2-4-seeded follicles. 

 Follicles dehiscent along both sutures; seeds shining. 



1 1. Opulaster. 



Follicles dehiscent along one suture; seeds'dull. , ,i, ,,,,., 

 Pistils alternate with the calyx-lobes. 2. Spiraea. 



Pistils opposite the calyx-lobes, petals white. 3. Porteriintlms. 

 Pistils numerous or rarely few, ripening, into 1^-2-seeded ^drupelets or 

 achenes., ,. , -, ....■....,,. 



Pistils ripening into drupelets crowded on the receptacle. 

 Drupelets very pulpy. 4. Rubus. 



Drupelets nearly dry, enclosed by the calyx. 5. : Dalibarda. . 

 Pistils ripening into aqhenes. 



Style deciduous. . 



Style nearly basal';' ovules ascending or nearly erect, ortho- 



tropous; leaves pinnate. "6.' Drymocallis. 



Style lateral; ovules ascending and amphitropous. 



Receptacle much enlarged and red in fruit; leaves 

 trifoliolate. 

 Receptacle pulpy, edible; petals white. 



• ; • ■,'■'• 7: Fragaria: 



. Receptacle not pulpy; .petals yellow. 



8. Duchesnea. 

 Receptacle not enlarged in fruit; ' leaves' interruptedly 

 pinnate; petals yellow.' ''■; ' ' 9. Argentina. 



Style terminal or nearly soi*. j.. i, • 



Pistils numerous; ovules pendulous and anatrppo.us. 



10. Potentitla. 

 Pistils 2-6; ovules basal, erect. ' 11. Tfral'dsteinia. 

 Style persistent on the achene. 12. ■ Geum: ; 



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



Calyx bearing hooted prickles ; petals 5. 13. Agrimonia. 



Calyx not prickly; petals none. 14. Sahguisorba. 



Fruit, numerous achenes, enclosed 'in .the '.fleshy receptacle; shrubs with pin- 

 nate leaves. 15. fiosa. 



1. OPULASTER Medic. 

 1. Opttlaster optjlifolius (L.) Kuritze. Ninebarlc. M. p. 492. ' Rocky 

 bahks''of streams ;■ of ten cultivated. Early summer. . ■• ■' ' ' 



'.' 2. SPIRAEA Li' ' 



Glabrous or nearly so throughout. 1. S. salicifolia. 



Twigs and lower surfaces of the leaves woolly-pubescent. 2. S. tomentosa. 



1. Spiraea salicipolia L. Meadow-sweet. M. p. 492. Wet or low grounds. 



Summer. 



2. Spiraea tomentosa L. Hardhacli, Steeple-bush. M. p. 492. Low 



grounds. Summer. 



3. PORTERANTHTJS Britton. 



1. Porteranthus trifoliatus (L.) Britton. Indian-physic, Bowman' s-root. 



M. p. .493. Rich woods. Summer. , 



Philadelphia— Wissahickon (Me.) (Re.) (Te.), Fairmount Park (Wn.). 



Bucks— Argus (Fr.), Lumberton, Delaware shore (Ws.). Montgomery 



— Shannonville (Or.), Mill Creek, Walnut Hill (VP.). Delaware — 



Media (Gi.) (Ws.), Wawa (Ja.) (U. C. S.), Valley of Darby Creek (B. 



