ROSE FAMILY 



149 



persistent, with an epicalyx of 5 or 4 bracteoles ; petals 5, rarely 

 4 ; stamens many ; carpels many, i-ovuled ; fruit an etaerio of 

 achenes on a small dry receptacle ; style not elongating. (Name 

 from the Latin potens, powerful, from the medicinal properties of 

 some species, especially, perhaps, of P. palustris, an astringent 

 tonic.) 



* Achenes glabrous or nearly so : receptacle concave 



1.* P. norvegica, with stem erect, 8 — 10 in. high; leaves 

 palmate ; and flowers yellow in crowded terminal racemes, has 

 been found in Burwell Fen, 

 Cambridgeshire, and in York- 

 shire, but has probably been in- 

 troduced with Norwegian timber. 

 Annual. 



2* P. hirla, with stem erect ; 

 leaves of 5 — 7 much-toothed 

 leaflets, obovate on the radical 

 and linear on the cauline leaves, 

 is also not indigenous. 



3. P. sterilis (Barren Straw- 

 berry). — Prostrate, without run- 

 ners, silky ; leaves ternate ; leaflets 

 obovate, crenate, very hairy 

 beneath j peduncles slender ; 

 flmvers white, not more than \ in. 

 across ; petals short, notched. — ■ 

 Banks and hedges ; abundant. 

 One of the earliest spring flowers, 

 often confounded by beginners 

 with the wild strawberry, from 

 which the above characters serve 

 to distinguish it. — Fl. January — 

 May. Perennial. 



4. P. verna (Spring Cinque- 

 foil). — A small woody hairy plant, about 5 in. long ; leaves of 5 — 7, 

 obovate serrate leaflets, hairy on the edge and on the veins 

 beneath j flowers yellow, 2 — 3 together, £ in. across. — Dry 

 pastures ; not common. — Fl. April — June. Perennial. 



5. P. Crdntzii (Alpine Cinquefoil). — A larger, more erect, but 

 closely allied species ; stem 4 — 10 in. high ; flowers 1 in. across. — 

 Alpine rocks in Scotland, Wales, and the north of England j 

 rare. — Fl. June, July. Perennial. 



6. P. erecia (Common Tormentil). — A small, sub-erect plant ; 

 rhizome woody; stems 6 — 10 in. high, slender, leafy, with curly 



POTENTfLLA ERECT A (C 



Tormentil). 



