ICOSANDRIA POLYGYNIA. 377 



236. POTENTILLA. 



* Leaves ternate.. 



P. norvegica: stem erect, dichotomous above; leaves ternate, petio- 

 late ; leaflets oblong, acutely serrate, with spreading hairs ; pedicels 

 axillary ; petals obovate, shorter than the calyx. 



HAB. Old fields. June Aug. <g> ; hairy, 8 inches high; stipules 

 large ; Jiowers yellow. 



* * Leaves digitate. 



P. canadensis : whole plant silky villous ; stem procumbent and as- 

 cending, somewhat branched ; leaves quinate obovate, incisely den- 

 tate ; peduncles solitary, elongated ; segments of the calyx linear- 

 lanceolate ; petals orbicular, nearly as long as the calyx. 



HAB. Fields and woods. April May, 3J. ; stem 2 10 inches high; 

 Jiowers yellow ; recept. hairy. 



P. simplex : stem sarmentose ; simple ; leaves quinate ; leaflets ob- 

 long oval, coarsely serrate, hairy beneath ; stipules incised; pedun- 

 cles axillary, solitary, elongated ; petals roundish obcordate, a little 

 longer than the calyx. 



HAB. Fields and woods. May Aug. Ij.; hairy; ped. \-Jlowered ; 

 Jiowers yellow. 



P. argentea : stem ascending ; leaves quinate ; leaflets cuneiform, in- 

 cised, revolute on the margin, white and tomentose beneath ; petals 

 retuse, a little longer than the calyx. 



HAB. Rocks and fields. June September, 71; often spreading; 

 leaves green above ; Jlower yellow. 



* * * Leaves pinnate. 



P. fruticosa : stem fruticose ; leaves pinnate ; leaflets oblong-lanceo- 

 late, very entire ; petals longer than the calyx. 



HAB. Bog meadows. June. A shrub 2 feet high ; much branched ; 

 Jlower yellow. 



P. Anserina: stem creeping; leaves interruptedly pinnate; leaflet* 

 numerous, incisely and very acutely serrate, silky ; pedicels axillary, 

 solitary, as long as the leaves ; stipules many -cleft. 



HAB. Wet meadows. June, Tj.; stems long; leaflets 7 10 pairs, 

 white beneath ; Jlower yellow. 



237. FRAGARIA. Strawberry. 



P. virginiana: leaflets broad-oval, smoothish above; the lateral one 

 distinctly petiolate ; hairs of the petiole spreading ; of the peduncles 

 appressed ; fructiferous ; calyx spreading. 



HAB. Fields and woods. May June, 7J- ; stem sarment. ; Jlower 

 white ; fr. red. 



