101 POTENTILLA TORMENTILLA 



branches (the lower ones apparently coming off opposite the 

 alternate leaves) , which repeatedly dichotomise at the opposite 

 leaves, the whole forming a very lax divaricate cyme. Calyx very 

 deeply cut into 4 lanceolate, acute, pale green, hairy, valvate seg- 

 ments, outside of which and alternating with them are 4 other 

 ones about half as long (epicalyx). Petals 4, roundish, with a 

 very short claw, spreading, lemon yellow with the base orange, 

 soon falling. Stamens about 16, inserted on the perigynous rim 

 (disk) of the calyx which is covered with white hairs, filaments 

 slender, shorter than the petals, yellow, anthers short, rounded. 

 Carpels few, about 6 8, distinct ; ovary small, tumid, glabrous ; 

 styles lateral, erect, yellow, thickened above. Achenia somewhat 

 kidney-shaped, keeled on the back, smooth, brown, with ridged 

 reticulation when dry. Seed solitary, pendulous, radicle superior, 

 no endosperm. 



Habitat. A very common plant in all parts of this country, 

 especially on heaths, dry fields, roadsides and woods, flowering 

 from July till late in the autumn. It is also found throughout 

 the continent of Europe and extends into the arctic regions, Siberia 

 and Iceland, but does not reach N. America. There are several 

 larger varieties with rooting stems, stalked leaves, and sometimes 

 5 petals, which appear to be intermediate between this species 

 and P. reptanSj Linn., the common Cinquefoil. 



Syme, E. B., iii, p. 146; Hook, f., Stud. Flora, p. 115; Watson, 

 Comp. Oyb. Br., p. 159; Willk. & Lange., Prod. Fl. Hisp., ii, 

 p. 233; Gren. & Godr., Fl. France, i, p. 530; Boiss., ii, p. 717; 

 Lindl., Fl. Med., p. 225. 



Official Part and Name. TOEMENTILLA, Tormentil ; the rhizome 

 (U. S. P. Secondary). It is not official in the British Pharma- 

 copoeia, or the Pharmacopoeia of India ; but it was formerly official 

 in the London, Edinburgh, and Dublin Pharmacoposias. 



General Characters and Composition. Tormentilla rhizome is 

 commonly known in this country as tormentilla root, and in the 

 United States, as tormentil. As seen in commerce in a dried 

 state it has usually an irregularly cylindrical form, but is some- 



