48 ROSACEAE 



P. leucocarpa Rydberg. A decumbent or ascending annual, 6-30 inches 

 high, pubescent or glabrate; leaves all 3-foliolate: leaflets oblong, cuneate, 

 thin, incisely-serrate: flowers terminal, loosely cymose; stamens about 10: a- 

 chenes small, glabrous. Reported from Woodbury county. (P. millcyruna 

 Watson. ) 



P. rivalis Nutt. Stem slender, branched, villous: leaves pinnately 5-folio- 

 late or 3-foliolate and the terminal leaflet 3-parted: cyme loose; calyx small: 

 petals minute: stamens 10-20. Reported from Fayette and Woodbury coun- 

 ties. 



t f Leaves more or less white tomentose; stamens 20-2.'). 



P. pennsylvanica L. Stems usually erect, 15-30 inches high; "ieaflets 

 5-9, grayish-tomentose beneath, glabrous above, oblong, obtuse, incisely-pin- 

 natitid into linear segments; flowers in a dense cyme; stamens 20-25. Re- 

 ported from Lyon and Jones counties. 



* * * Perennial; flowers purple; receptacle hairy, becoming large and spongy; 



style lateral ; achenes glabrous. 

 P. palustris (L.) Scop. Base decumbent, woody, perennial; stem jrla- 

 brous below, pubescent above; leaves pinnate, the lower long-petioled, 5-7 fo- 

 liolate; leaflets oblong or oval, serrate; flowers few, showy, in an open cyme: 

 calyx with narrow bractlets, purple within; petals shorter, purple: stamens 

 many. Swampy places; June-August; infrequent; Emmet, Cerro Gordo, and 

 Hancock counties. (Comarum palustre L.) 



* * * * Shrubby perennials ; receptacle and achehes villous; style attached below 



the middle. 



P. fruticosa L. Erect, shrubby, %-3 feet high, much branched, bark 

 shreddy; leaflets 5-7, oblong, entire, silky, margins revolute; petals yellow, 

 orbicular; stamens 15-20. Rocky bluffs; June-September: infrequent; Win- 

 nishiek and Allamakee counties. 



P. tridentata Ait. Stems tufted, woody, 1-L0 inches high: leaves petioled, 

 3-foliolate; lower leaflets oblanceolate, cuneate toward the base, apex trun- 

 cate, 3-toothed or sometimes 2-6-toothed, upper leaflets linear or oblong, of- 

 ten entire; petals white; stamens about 20. Rocky places; June-August; re- 

 ported from Winneshiek county. 



* » * # * Herbaceous perennials; flowers solitary, on slender axillary peduncles, 



yellow; styles slender, lateral achenes glabrous. 



P. canadensis L. Stems slender, prostrate or decumbent; leaves petioled, 

 digitately 5-foliolate: leaflets oblanceolate or oblong, obtuse at the apex, ser- 

 rate; stamens about 20. Dry soil, woods and fields; April-August; common. 



P. anserina L. Leaves petioled, pinnate; leaflets 7-25, oblong to obovate, 

 obtuse, serrate, white and silky-pubescent beneath. Abundant along rail- 

 road embankment at Jewel Junction, Hamilton county. (Hitchcock). 



AGRIMONIA L. Perennial herbs, with alternate interruptedly pinnate 

 leaves, and small yellow flowers in spike-like racemes. Calyx-tube inversely 

 conical, constricted at the throat, armed with hooked prickles on the upper 

 portion, 5-cleft, hardened in fruit, and enclosing the 2 achenes. Petals 5. 

 Stamens 12-15. Styles terminal. 



A. hirsuta (Muhl.) Bicknell. Stem 2-4 feet high, erect, simple, hairy, 

 from fibrous roots; leaflets 5-7, with minute ones intermixed, elliptic to 

 broadly oblong, coarsely dentate, usually glabrous below; petals twice the 

 length of the reflexed sepals. Woods; July-August; common. (A. cupatoria L. 

 of Gray's Manual.) 



