176' FLORA OF PHILADELPHIA. 



9. AEGENTINA Lam. 

 1. Argentina Anserina (L.) Rydb. Silver-weed. M. p. 502. Ballast. 

 Summer. 

 Philadelphia — Greenwich Point (Te.). 

 Camden — Kaighn 's Point. 



10. POTENTILLA L. Cinquefoil. 



Flowers cymose ; erect or ascending herbs. 



Leaflets 5-7. 1. P. argentea. 



Leaflets 3. 2. P. Monspeliensis. 



Flowers solitary, axillary; creeping or ascending plants. 



Stem long-assurgent ; first flower from the axil of the second stem-leaf 



or some subsequent leaf. 3. P. Canadensis. 



Plant low, less than 1 dm. high ; first flower from the axil of the first 

 stem-leaf. 4. P. pumila. 



1. Potentilla argentea L. M. p. 503. Dry, barren fields. Summer. 



J5?icA,s— Sellersville (Fr.). Z)eZaw'a?-e— Swarthmore (Fu.) (Pr.). North- 

 ampton— (P.). • 



Camden — Ballast (C). Gloucester — MuUica Hill (C). Ocean — 

 Forked River (Mac). Monmouth — 'North side of Deal Lake, Belmar 

 (Wn.), Phalanx (C). Mercer— Trenton (C). fl'Mnfe?-(^o?i— Lambert- 

 ville (C). 



2. Potentilla Monspeliensis L. M. p. 504. Dry soil. Summer. 



3. Potentilla Canadensis L. Wild Strawberry. M. p. 506. Dry soil. 



Summer. 



4. Potentilla pumila Poir. M. p. 506. Poor soil. Summer. 



11. WALDSTEINIA Willd. 

 1. Waldsteinia fragarioides (Michx.) Tratt. Barren Strawberry. M. p. 

 506. Wooded hillsides. Early summer. 

 BmoA's— Sellersville (Fr.). Morji^^ower^/— Green Lane (VP.). Series— 

 Hamburg (Cr.). Northampton— Haston (Ca.). 



12. GEUM L. AvENS. 



Calyx-lobes strongly reflexed; style not plumose, sometimes hispid at base. 

 Flowers yellow, 4 mm. broad ; head of fruit stalked, calyx bractless. 



1. G. vernum. 

 Flowers 6-20 mm. broad; head of fruit sessile, calyx bracteolate. 



Petals white, or very nearly so, obovate. 



Plant softly-pubescent or glabrate; receptacle bristly. 



2. G. Canadense. 

 Plant rough-pubescent ; receptacle glabrous or downy. 



3. G. Virginianum. 

 Petals cream-yellow, narrowly oblong, scarcely exceeding the sepals. 



4. G. flavum. 

 Petals yellow, broadly obovate or orbicular. 



Segments or lobes of upper stem-leaves broadly rhombic ovate ; 

 petals 4-6 mm. long. 5. G. macrophyllum. 



Segments or lobes of upper stem-leaves oblanceolate ; petals 

 6-8 mm. long. 6. G. strictum. 



Calyx-lobes erect or spreading; style plumose below; flowers purple, nod- 

 ding. 7. G. rivale. 



