RO8ACELB. (ROSE FAMILY.) 119 



* Achenia glabrous : style thickened above : receptacle txmical in Jhat. 



7. P. arguta, 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 and westward. July. 



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



8. P. Aiiserina, 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. (Eu.) 



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 CINQUB-FOIL.) Stems low 

 (4 7 - 6' high), rather woody at the base, tufted, ascending, cymosely several- 

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

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

 on mountains ; Cape Cod, Cape Ann, and in Maine at the level of the sea ; 

 shore of Lake Superior and northward. June. 



3. Styles modei-aiely lateral : petals (shorter titan the calyx, ovate-lanceolate) and 

 Jilaments 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. ]\. (Comarum palustre, L.) Bogs, 

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



12. FRAGARIA, 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. Virginiana, Ehrhart. Achenia embedded in the deeply pitted recep- 

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

 shorter than the leaves, which are of a rather coriaceous or linn texture Fruit 

 roundish-ovoid 



