MEMOIRS FROM THE DEPARTMENT 5P BOTANY OF COLUMBIA UNIVERSITY 2? 



Leaves coarsely toothed or cleft about half-way to the midrib. 



Leaves white-silky on both sides ; plant low. 46. P. Candida. 



Leaves greenish above, densely white-tomenitose beneath. 



Stem slender ; leaflets oblanceolate, the teeth triangular. 47. P. gracilis. 



Stem stout ; leaflets obovate ; teeth ovate or oblong. 48. P. Maschkeana. 



Leaves silky or somewhat tomentulose beneath. 



Segments linear ; leaves more or less silky. 53. P. pectenisecta. 



Segments oblong or triangular ; leaves green, slightly tomentulose beneath. 49. P. viridescens. 

 Leaves green on both sides. 



Plant stout, more or less hirsute. 



Petals slightly exceeding the sepals, deep yellow. 

 Stamens about 20 ; native. 

 Stamens about 30 ; introduced. 

 Petals exceeding the sepals by one-half, sulphur yellow. 

 Plant slender, slightly silky. 

 Leaflets divided to near the midrib. 



Leaves silky and somewhat tomentulose beneath. 

 Leaves densely tomentose beneath. 

 Margin revolute. 

 Margin not revolute. 



§ 10. SUBJUGAE. 



This group,. as well as the Ruhricaules, form the connection between the Graciles on 

 one hand and the Niveae and the Leucophyllae on the other. There is a combination of 

 digitate and pinnate characters in the leaves. In P. subjuga the pinnate tendency is seen 

 in the small leaflets on the petiole ; and in P. quinquefolia in the petiolate middle leaflet. 

 The species are in size intermediate between P. gracilis or P. pulcherrima and P. nivea 

 and much resemble depauperate forms of either of the two first or an over-developed P. 

 nivea. 



Basal leaves digitately 5-foliolate with an additional small pair of leaflets on the 



petiole. 56. P. subjuga. 



Basal leaves digitately 5- (seldom 3-) foliolate with the middle leaflet petiolate. 57. P. quinquefolia. 



§11. OVALES. 



Low plants with the habit of a Fragaria, white flowers, 3-foliolate leaves and 3- 

 toothed sepals. 



One Mexican species. 58. P. ovalis. 



