POTKNTILI.A. ROSACE^E. 437 



Pastures, road-sides, and waste places throii^lioiit the Northrrn nnd INlKidlo 

 States! as a weed; also in S. Cnrolina, Ellinlt ; apparrntly inirodiicrd ; 

 but indifrenoiis in the northern part of New 'N'ork ! and throii<;hoiit (Canada! 

 to Labrador ! Aretie America, Oregon, Norll)lU Sound I and Silelia. -Inly- 

 AujT. — N(.'iiher the mode of ijrowlli, nor the 1(K)thin£j of the h-avcs iiirnisli any 

 constant cliaraetcr to (Hstins^nish ihe P. hirsula. The achenia in some siicei- 

 mens an? ahuost even, in others strongly striafe-nifrose or rilibed ; hui l)oth 

 forms occur as well in the true P. Ncjrvegiea as in the P. hirsuta. Koch de- 

 scribes the radical leaves as pinnate with 2 pairs ; but this we have never 

 observed. 



--*■■ 2. P. rivalis {NiWt.l mss.) : " elotlied with soft somewhat viscous pubes- 

 cence; stem erect, much branched ; radical leaves piimately 5-lbliolaie ; the 

 leaflets crowdeil, and the .'3 up])er ones confluent; those of tlie cauline leaves 

 3, often confluent, oblong, cuneit()rm at the base, coarsely serrate ; stipules 

 ovale, nearly entire ; flowers numerous, small, on rather short pedicels; 

 calvx-segments acute ; petals inconspicuous ; achenia smooth and even. 



"'in alluvial soil along the Lewis River." July. — A very distinct species, 

 allied to P. Norvegica. Cauline leaves small. Flowers inconspicuous, 



-^"" 3. P. paradoxa (Nutt. ! mss.) : " decumbent at the base ; pubescent ; leaves 

 ■ pinnate ; leaflets 7-9, obovate-oblong, incised, the upper ones confluent; sti- 

 pules ovate, mostly entire ; peduncles [alar] solitary, recurved in fruit; 

 calyx-seginents all nearly e(|ual, acute, about the length of the obovate pe- 

 tals ; receptacle villous ; achenia striate, 2-Iobed ; the lower portion (the en- 

 larged base or insertion fil[e<l with starch) as large as the proper carpel. 

 P. supina, Mkhx. Jl. 1. p. 304 ; Huoh. l. c. ; not nC Linn." 



Banks of tiie great western rivers, the Ohio I Mississippi ! Missouri ! &c. 

 to Oreaon. {?suttaU) — We observe tlie curious dejjosition of starchy matter at 

 the base of the carpels, pointed out by Mr. Nutlall, forming, as it were, a kind 

 of albumen exterior to the seed : but otherwise our plant minutely resembles 

 the European, and especially the Siberian forms of P. supina ; except that it 

 is usually smaller, and Mr. Nutlall suspects it to be perennial. 



* * Perennial (achenia smooth) : leaves pinnate ; the leaflets sometimes crowded 

 or almost palmate, 



4. P. sericea (Linn.) : flowering stems ascending, 1-2-leaved, few-flow- 

 ered ; leaflets 9-11, crowded, oblong, pinnatifld, silky-tomentose on both 

 sides, whitish beneath ; stipules lanceolate, mostly entire. — Lehm. ! Pot. p. 

 66, t. 6 ; DC. ! prodr. 2. p. 582. P. dasyphylla,"^ Ledeb.Jl. Alt. ? 



0. glahrnta (Lehm.) : older leaves much less tomentose. — Lehm. ! in 

 Hook.fl. Bar.- Am. 1.2}- 1B9. 



Rocky Mountains between latitude 52'' and 5G°, Drummond ! {fi. only) 

 — A Siberian species. 



5. P, ejfusa (Dougl.) : canescently tomentose ; stem ascending, weak ; 

 leaves interruptedly pinnate ; leaflets ol)long, incisely serrate ; flowers di- 

 chotomously cymose ; stipules lanceolate, acuminate, entire ; segments of the 

 calyx acuiiiinate; e(|uaUing the obcordate petals. — Lehm. ! stirp. pug. 2. p. 

 8, Sf in Hook. I. c. 



p. Jiiicaulis {Suit. \ mss.): "flowering stems filiform (about 3 inches 

 high), few-flowered ; leaflets unequally incised." 



y. gossypina (Nvitt. ! mss.) : "very tomentose and soft; stem nearly erect, 

 leafy ; leaflets incisely but not deeply serrate." 



On the Assiniboin River, &c., Douglas ! 0. Rocky Mountains towards 

 the sources of the Platte, Nutlall ! July. — Stem about a foot high. Brae- 



