Obder 47.— R0SACBJ3. 343 



to a foot or more in length. PI3. yellow, on long pedioela. Cal. segm. lanceolate 

 or linear. Apr. — Aug. 



/3. PUMILA T. & G. Very small and delicate, flowering in Apr. and May, 



everywhere ; sts. a few inches long. (P. pumila Ph.) 

 y SIMPLEX T. & G. Plant less hirsute ; st simple, erect or ascending at base ; 

 Ifla. oval-cuneiform. Flowering Jn. to Aug. in richer soils. Stg. 8 to 14' 

 high. Lfts. about 1' long, f as wide. (P. simplex Mx.) 



5 P. argSntea L. St. ascending, tomentous, branched above ; Ifls. oUong-amei- 

 form, with a few, large, incised teeth, smooth above, silvery canescent beneath, 

 sessile ; fls. in a cymous corymb ; petals longer than the obtusish sep. — ^A pretty 

 plant, on dry or roelcy hills, Can. and N. States, remarkable for the silvery white- 

 ness of the lower surface of the Ivs. Sts. 6 to 10', long, at length with slender 

 branches. Lfts. 5 to 9" by 1 to 2", with 2 or 3 slender, spreading teeth each 

 side ; upper ones Unear, entire. Pis. small ; cal. canescent ; petals yellow. Jn. 



Sept. 



6 P. r^ota "Willd. Erect, simple, pubescent ; lfts. 5 to '7, oblong or oblanoeolate, 

 coarsely serrate, with large, cleft stipules ; fls. in a terminal, expanding oymo ; 

 petals obcordate, longer than the ovate, acute sep. — Cultivated and sparingly 

 naturalized, N. Eng. to Ohio. St. 1 to 2f high. Pis. light yellow. 



7 P. frutioosa L. St. fruticous, very branching, liirsute, erect; lfts. 5 to 1, lin- 

 ear-oblong, all sessile, margin entire and revoluto ; petals large, much longer than 

 the calyx. — A low, bushy shrub, N. States (Niagara Falls, Willoughby Lake, Vt. 

 eta) and Brit. Am. Sts. 1 to 2f high, with a reddish bark. Petioles shorter than 

 the leaves. Leaf about 1' by 2'', acute, crowded, pubescent. Stip. nearly as 

 long as the petioles. Pis. 1' diam., yellow, in terminal clusters. Jn., Aug. (P. 

 floribunda, Ph.) 



8 P. anserina L. Silvee Weed. Goose Grass. St. slender, creeping, pros- 

 trate, rooting ; Ivs. interruptedly pinnate, lfts. many pairs, oblong, deeply serraf e, 

 canescent beneath; ped. solitary, 1-flowered, very long. — A fine species, on wet 

 shores and meadows, N. Eng. to Arc. Am. Sts. subterraneous, sending out 

 reddish stolons 1 to 2f long. Petioles mostly radical, 6 to 1 0' long. Lfts. 1 to 

 1 J' by 3 to 6", sessile, with several minute pairs interposed. Ped. as long as the 

 Ivs. Pis. yellow, 1' diam. Jn. — Sept. 



9 P. parado^za Nutt. Decumbent at base, pubescent; Ivs. pinnate, lfts. 7 to 9, 

 obovate-oblong, incised, the upper ones confluent ; stip. ovate ; ped. solitary, re- 

 curved in fruit ; petals obovate, about equaling the sep. ; ach, 2-lobed, the lower 

 portion a thick, starchy appendage. — River banks, Ohio to Oreg., Isl. opposite St. 

 Louis. St. 8 to 12' long. Lfts. 6' long, scarcely larger than the entire stipilles. 

 Jn., JI. (P. supina Mx.) 



10 P. Peiinsylvanioa L. . Erect, canescently tomentous or soft-villous ; lfts. 5 

 to 9, oblong, obtuse, pinnatifid or pectinate, upper ones crowded or confluent, 

 larger ; cyme fasiigiate, at length expanding ; petals emarglnate, scarcely longer 

 than the acute sepals. — N. Eng. (Pursh.), Can. K "W. to Siberia. (P. peotinata 

 Pisoh.) 



11 P. argiita Ph. Erect, grayish, pubescent and villous ; radical Ivs. on long 

 petioles, 7 to 9-fohate, cauline few, 3 10 7-foIiate, lfts. broadly ovate, cut-serrate, 

 crowded ; Jls. in dense terminal cymes. — ^Along streams, etc.. Can. and K States, 

 W. to the Rocky Mts. St. 2 to 3f high, stout, terete, striate, and with nearly 

 the whole plant very hairy. Radical ivs. one foot or more long ; lfts. 1 to 2' by 

 8 to 16", sessile, odd one petiolulate. Fls. about 8'' diam. ; pet. roundish, yel- 

 lowish white, longer than the sepals ; disk glandular, 5-lobed ; anth. blackish, 

 with a white border. May, Jn. (P. oonfertiflora Hitchcock. Boottia sylves- 

 tris Bw.) 



25. SIBBAL'DIA procmnbens, L. " Mountains of Can. and Vt." 

 (Pursli) ; but not since found within our limits. 



26. SPIR-zE^A, L. (Gr. OTreipa, a cord or wreath ; the flowers are 

 or may be used in garlands.) Calyx 5-cleft, persistent ; petals 5, round- 

 ish ; stamens 10 to 50, exserted ; carpels distinct, 3 'to 12, follicular, 



