218 CLASS XII. ORDER V. 



with hairy petioles. Leafcts obovate, obtuse, their upper half 

 deeply serrated, glabrous above, paler and hairy underneath. 

 Stipules hairy, acute, those of the stem about six cleft. Pedun- 

 cles solitary, slender, hairy, longer than the petiole which springs 

 from the same joint. Calyx segments hairy, acute, some of them 

 furnished with a small tooth or two. Petals roundish, retuse, a 

 little longer than the calyx. Anthers sagittate. 



During the summer a fleshy thickening often takes place in 

 various parts of the stem, apparently caused by insects. The 

 flowers reappear in October. 



Very distinct from P. simplex, though quoted by Pursh and 

 Torry as synonymous. It is much smaller, flowers a month 

 earlier, and is never erect. 



PoTENTiLLA NoRVEGicA. L. Norioay Clinquefoil. 



Leaves ternate; stein dicliotomoiis; peduncles axil- 

 lary. L. 



An erect, hairy plant. Stem round, straight, forked at top. 

 Leaves in threes, oval, cut-serrate, iheir petioles and veins cov- 

 ered with long hairs. Stipules ova'e, acute, somewhat toothed. 

 Flowers numerous, axillary and terminal, somewhat crowded. 

 Petals yellow, shorter than the calyx. — By road sides and thick- 

 ets. — July. — Perennial. 



PoTKNTiLLA TRiDENTATA. L. Mountaiii PotentUla. 



Leaves ternate, evergreen ; leafets wedge-shaped, 

 three toothed at tlie end ; pedtnicles few fiowered. 



A suffruticose alpine plant of all our northern mountains. 

 The lower part of the stem is woody, prostrate, rooting, with 

 subulate stipules at the top, below the leaves. Petioles short, 

 slightly hairy. Leafets three, sessile, smooth, coriaceous, ob- 

 long-wedge shaped, uniformly ending in three nearly equal teeth. 

 Flowering stalk hairy, with several small, ternate, lanceolate 

 leafets. Flowers iew. in a sort of irregular corymb. Calyx acute, 

 the narrow segments more obtuse. Petals oblong, white, longer 

 than the calyx. — Abundant on the summit of Wachusett. On 

 the Wiiite mountains, Moosehillock, &c. In the college yard at 

 Brunswick. — June. 



