Rose Family. 47 



latum Pursh. i 



FRAGAF^IA L. Strawberry. Stemless perennial stoloniferous hairy herbs, 

 with trifoliolate radical leaves, and white scapose poh'gamo-dioecious flowers. 

 Calyx deeply .Vcleft. with 5 narrow bractlets at the base of the sinuses giving 

 it the appearance of being- 10-cleft. Petals 5, obcurdate. Stamens and stj'les 

 many. Receptacle in fruit becoming- globose or conical, pulpy, scarlet, bear- 

 in y the dry achenes on or near the surface. 



p virginiana Duchesne. Stout, tufted, more or less villous-pubescent: 

 leaflets obovate-euneate, coriaceous, serrate: calyx becoming erect-spreading-: 

 achenes imbedded in pits of the oblong* receptacle. Fields and woods: May- 

 June: common. 



p. vesca L. Fruiting receptacle conical, without pits: achenes projecting- 

 on the nearl\* even surface: fruiting calyx spreading orreflexed: leaflets thick- 

 ish. Introduceo; May: reported from several counties but is confused with 

 the following- species. 



F. americana Porter. Villous-pubescent or glabrate, runners produced 

 freely: leaflets thin, ovate or oval, the terminal cuneate-ovate. all incised- 

 dentate: fruit ovoid or elongaied-conic, reddish or pink, achenes borne on the 

 even surface. Rocky woods: May-June: infrequent: forms from Winneshiek. 

 Johnson, and Decatur counties referred to this species. 



POTENTILLA L. Herbs or shrubs, with alternate stipulate compound 

 leaves, and solitary or cymose flowers. Calyx ">-lobed. 5-bracteoIate. Petals 

 5. Stamens many. Achenes many, collected in a head, on a dry usually pu- 

 bescent or hairy receptacle. 



* Perennials;; flowers ivJiitc; style nearly basal. 



P. arguta Pursh. Glandular ChiwpiefoiL Stem 1-4 feet high, mostly sim- 

 ple, glandular and brownish-hairy: basal leaves petioled. pinuately 7—1 1-foli- 

 olate, leaflets incised dentate, the lateral ovate, oval orrhomboid. the termin- 

 al one cuneate: stem-leaves short-peti.ded or sessile, leaflets fewer: flowers 

 white, cyme dense: stamens 25-30, borne on a thick glandular disk. Prairies; 

 June-July; common. 



** Annual or biennial, flowers yellow; style terminal. 

 \ Leaves not nhitetomentosc; stamens 5-20. 



P. norvegica L. Annual or biennial. 6-30 inches high, hirsute leaves ter- 

 nate. basal and lower petioled, the upper sessile: leaflets obovate. obtuse, in- 

 cisely-serrate. pubescent; flowers small, in a close leafy cyme: calyx larg-e, 

 lobes ovate: petals obovate. retuse. shorter than the calyx-lobes: stamens 15- 

 20. Dry soil: June-September: common. ( P montspellensls L.) 



P. paradoxG Nutt. Stems decumbent to erect, subvillous. 1-3 feet high: 

 leaves mostly petioled. pinnately . r »-ll-foliolate: leaflets obovate or oval, ob- 

 tuse: flowers in a loose leafy cyme: stamens about 20: achenes g-labrous, 

 strongly gibbous. Wet soil, shores: June-September; frequent; Cerro Gordo, 

 Dickinscn. and Woodbury counties. ( P. siijtina L. of Gray's Manual. ) 



P. nicolletii I Wats.) Sheldon. Similar to the preceding- but leaves mostly 

 3-foliolate; flowers falsely racemose: stamens 10-15. Reported from Iowa. 



P. pentandra Engelm. Stem 1-4 feet high, erect, hirsute, branched a- 

 bove; basal and lower leaves petioled. 3-foliolate. the lateral leaflets deeply 

 parted, the upper ternate: leaflets oblanceolate or oblong, obtuse, incised-den- 

 tate: flowers terminal, more or less cymose: stamens 5-8, when 3 opposite the 

 sepals. Reported from Scott. Story. Humbolt. Woodbury, and Fremont 

 counties. 



