ROBACBJB. (ROSE FAMILY.) 119 



* Achenia glabrous : style thickened above : receptacle conical in fruit. 



7. P. argn&ta, Pursh. Stem erect and stout (2 -4 high), brownish 

 hairy, clammy above ; leaves pinnate, of 3 - 9 oval or ovate cut-serrate leaflets, 

 downy underneath; flowers cymose-clustered ; petals yellowish or whitish; disk 

 thick and glandular. Rocky hills ; common northward. July. 



* * Achenia (at least below) and the convex receptacle vittous. 



8. P. Aliserina, L. (SILVER- WEED.) Herbaceous, creeping by slen- 

 der rooting runners ; leaves all radical, pinnate; leaflets 9-19, with minute pairs 

 interposed, oblong, pinnatifid-serrate, green and nearly smooth above, silvery- 

 white with silky down underneath ; stipules many-cleft ; flowers solitary (yellow), on 

 long scape-like peduncles. Brackish marshes, river-banks, &c., New England 

 to Penn., Wisconsin, and northward. June -Sept. (En.) 



9. P. fruticosa, L. (SHRUBBY CINQUE-FOIL.) Stem erect, shrubby 

 (2 -4 high), very much branched; leaves pinnate ; leaflets 5-7, closely crowd- 

 ed, oblong-lanceolate, entire, silky, especially beneath ; stipules scale-like ; 

 flowers numerous (yellow), terminating the branchlets. Bog-meadows; same 

 range as the last. June - Sept. (Eu.) 



10. P. tridentata, Ait. (MOUNTAIN CINQUE-FOIL.) Stems low 

 (4' -6' high), rather woody at the base, tufted, ascending, cymosely several- 

 flowered ; leaves palmate ; leaflets 3, wedge-oblong, nearly smooth, thick, coarsely 

 3-toothed at the apex ; petals white ; achenia and receptacle very hairy. Rocks, 

 on mountains ; and in Maine near the level of the sea ; shore of Lake Superior 

 and northward. June. 



4 3. Styles moderately lateral : petals (shorter than the calyx, ovate-lanceolate) and 

 filaments more or less persistent : disk thick and hairy: achenia glabrous: recepta- 

 cle hairy, convex, at length large and spongy. (Comarum, L.) 



11. P. palustris, Scop. (MARSH FIVE-FINGER.) Stems ascending 

 from a creeping base (l-2 high) ; leaves pinnate, of 5-7 lanceolate or oblong 

 crowded serrate leaflets, whitish beneath; flowers somewhat cymose ; calyx (!' 

 broad) dark purple inside; petals purple. U (Comarum palustre, L.) Bogs, 

 N. England to Penn., Wisconsin, and northward. June -Aug. (Eu.) 



12. F RAO ARIA, Tourn. STRAWBERRY. 



Flowers nearly as in Potentilla. Styles deeply lateral. Receptacle in fruit 

 much enlarged and conical, becoming pulpy and scarlet, bearing the minute dry 

 achenia scattered over its surface. Stemless perennials, with runners, and with 

 white cymose flowers on scapes. Leaves radical: leaflets 3, obovate-wedge- 

 form, coarsely serrate. Stipules cohering with the base of the petiole, which 

 with the scapes are usually hairy. (Name from the fragrance of the fruit.) 

 The two species are indiscriminately called WILD STRAWBERRY.) 



1. F. Virgliiijina, Ehrhart. Achenia embedded in the deeply pitted recep- 

 tacle. Fields anl rocky places ; common. April - June. Scapes commonly 

 shorter than the haves, which are of a rather coriaceous or lirm texture. Fruit 

 roundish-ovoid. 



