PoTENTiLLA. XLVIII. ROSACEA. 251 



minute, subulate ; sep. spreading, long-acuminate, shorter than the narrow-obo- 

 vate, emarginate petals; sty. 00. — A delicate house-plant, with snow-white 

 double flowers. Native of Mauritius. 



12. POTENTILLA. 



Lat. potentia, power; in allusion to its supposed potency in medicine. 



Calyx concave, deeply 4 — 5-cleft, with an equal number of alter- 

 nate, exterior segments or bracteoles ; petals 4 — 5, obcordate ; sta- 

 mens 00 ; filaments slender ; ovaries collected into a head on a small, 

 dry receptacle ; styles deciduous ; achenia 00. — Herbaceous or shrubby. 

 Lvs. ^innately or palmately compound. Fls. solitary or cymose, mostly 

 yellow. 



* Leaves palmately trifoliate. 



1. P. NoRVEGiCA. Nonoegiaii Poientilla or CinquefoU. 



Hirsute ; st. erect, dichotomous above ; Ifts. 3, elliptical or obovate, den- 

 tate-serrate, petiolulate ; cymes leafy ; cat. exceeding the emarginate petals. — 

 Old fields and thickets. Arc. Am. to Car. Stem 1— -4f high, covered with silky 

 hairs, terete, at length forked near the top. Cauline petioles shorter than the 

 leaves. Leaflets J — \l' by \ — i', (lower and radical ones very small,) often 

 incised. Stipules large, ovate, subentire. Flowers many, crowded, with pale 

 yellow petals shorter than the lanceolate, acute, hairy sepals. Jl. — Sept. 



a. 7 hirsuta. T. & G. (P. hirsuta. Michx.) — Hairs loose, silky ; 5/. slender, 

 erect, subsimple ; loioer and middle lvs. equal, long-petiolate ; Ifts. roundish-obo- 

 vate, sessile, incisely dentate ; Jls. few, petals rather conspicuous, nearly as long 

 as the calyx. — Dry fields. With reluctance I adopt the views of Torrey & Gray 

 in regard to this plant. 



2. P. TRiDENTATA. Ait. Trident or Mojuilain Poientilla. 



Smooth ; St. ascending, woody and creeping at base ; Ifts. 3, obovate-cune- 

 ate, evergreen, entire, with 3 large teeth at the apex; cymes nearly naked; pet. 

 twice longer than the calyx. — On the White Mts. ! and other alpine summits in 

 the N. States. Flowering stems 6 — 12' high, round, often with minute, ap- 

 pressed hairs. Petioles mostly longer than the leaves. Leaflets sessile, 9 — 18" 

 by 4 — 6", coriaceous, smooth. Flowers with white, obovate petals. Carpels 

 and achenia with scattered hairs. Jn. Jl. 



3. P. MINIMA. Haller. 



St. pubescent, a.scending, mostly 1-flowered ; lvs. trifoliate ; Ifts. obovate, 

 obtuse, incisely serrate, with 5 — 9 teeth abov'e ; pet. longer than the sepals. — 

 Alpine regions of the White Mts. Stems numerous and leafy, 1—3' high. 

 Leaflets with the margins and veins beneath hairy. Flowers small. Petals 

 obcordate. Bracteoles oval-obtuse, narrowed at the base. 

 ♦ ♦ Leaves palmately 3 or b-foliaie. 



4. P. Canadensis. (P. sarmentosa. Willd.^ Common Cinqucfoil. 



Villo.se pubescent ; 5^. sarmentose, procumoent and ascending ; lvs. pal- 

 mately 5-foliate, the leaflets obovate, silky beneath, cut-dentate towards the 

 apex, entire and attenuate towards the base ; stip. hairy, deeply 2 or 3-cleft, or 

 entire; pedicels axillary, solitary; bracteoles of the calyx longer than the seg- 

 ments, and nearly as long as the petals. — Conmion in fields and thickets, U. S. 

 and Can. Stems more or less procumbent at base, from a few inches to a foot 

 or more in length. Flowers yellow, on long pedicels. Calyx segments lanceo- 

 late or linear. Apr. — Aug. 



[i. piuni/a. T. & G. (P. purnila. Ph.) — Very small and delicate, flowering 

 in Apr. and May. — I cannot perceive any diflerence between this and the above, 

 except its diminutive size and early flowering. In drv, sandy soils. Stems 

 about 3' high. 



y. simplex. T. & G. (P. simplex. Michx.) — Plant less hirsute ; .^t. simple, 

 erect or ascending at base ; ///.<c. oval-cuneilbrm ; flowering in June — Aug.— In 

 richer soils. Stems 8—11' high. Leaflets about 1' long, i as wide. 



5. P. AROENTEA. SHvenj CinqvcfoH. 



St. ascending, tomentose, branched above; Iffs. oblong-cuneifonn, with a 

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