Potentilla. ROSACE^E. 177 



t 

 trifoliolate, the leaflets obovate-cuneate, coarsely toothed ; flowers few, cymose upon 



short erect scapes. 



A small genus widely distributed through the temperate and alpine regions of the northern 

 hemisphere, and also in the Andes. Many species have been proposed, but scarcely half a dozen 

 are now recognized by botanists. Their unstable character and "the great facility with which 

 fertile cross-breeds are produced, give reason to suspect that the whole genus may prove to con- 

 sist of but one species " (Bentham). Many varieties are in cultivation, some of which flourish 

 with special luxuriance in this State. The three first following are the generally acknowledged 

 .North American species : but it is difficult to make a satisfactory reference of all the Californian 

 forms as found in collections. 



1. F. Virginiana, Ehrhart. "Akenes imbedded in the deeply pitted fruiting 

 receptacle, which usually has a narrow neck : calyx becoming erect after flowering 

 and counivent over the hairy receptacle when sterile or unfructified : leaflets of a 

 firm or coriaceous texture : the hairs of the scapes, and especially of the pedicels, 

 silky and appressed." Gray, Manual, 155. 



Var. Illinoensis, Gray, 1. c. " A coarser or larger plant, perhaps a distinct 

 species, the flowers more inclined to be polygamo -dioecious, the villous hairs of the 

 scape and pedicels widely spreading." F. Grayana, Vilmorin. 



The typical form of this species seems to be confined to the Atlantic States. The variety ex- 

 tends westward to the Rocky Mountains and it is said even to Washington Territory and Oregon. 

 If found in the northern part of the State it should be distinguished from the following species 

 by the characters of the fruit. The leaflets are cuneate-obovate, rounded at the summit. 



2. F. vesca, Linn. " Akenes superficial on the glabrous conical or hemi- 

 spherical fruiting receptacle (not sunk in pits) : calyx remaining spreading or re- 

 flexed : hairs on the scape mostly widely spreading, on the pedicels appressed : 

 leaflets thin, even the upper face strongly marked by the veins." Gray, 1. c. 



This European species is also widely indigenous through North America, and specimens from 

 the Sierra Nevada have been referred to it. It is doubtful, however, whether it is really found 

 within the State. The leaflets are usually less obtuse than in the last. 



3. F. Chilensis, Ehrhart. Usually low, densely villous with silky hairs, spread- 

 ing upon the petioles, scapes and pedicels, appressed upon the under side of the 

 leaves and the calyx : scapes and petioles rather stout : leaflets thick, perfectly 

 smooth above, cuneate-obovate, rounded at the summit : flowers large (often an inch 

 broad) : calyx lobes and bractlets elongated, entire : fruit not described. Torr. <fc 

 Gray, Fl. i. 448. 



Near the sea, from San Francisco to Alaska ; identical with the Chilian form. 



4. F. Californica, Cham. & Schlecht. Low, somewhat villous with spreading 

 hairs, which are less closely appressed on the under side of the leaves and calyx : 

 scapes and petioles usually slender : leaves thinner, cuneate-obovate and rounded, 

 sparingly villous on the upper side: flowers half an inch broad: calyx-lobes shorter, 

 often toothed or cleft : fruit small ; akeues superficial. Linnaea, ii. 20. F. lucida, 

 Vilmorin; Gay, Ann. Sci. Nat. 4 ser. viii. 201. F. vesca, Benth. PI. Hartw. 309; 

 Seem. Bot. Herald, 282. 



From San Diego to Mt. Diablo (Brewer) and the Oakland Hills (Holder) ; also in North- 

 western Mexico, Seemann. This appears to be distinct from the ordinary F. vesca, and from 

 other Californian forms. 



14. POTENTILLA, Linn. FIVE-FINGER. 



Calyx persistent, concave or flattish ; limb 5-lobed, with 5 alternate bractlets, 

 valvate. Petals 5, obcordate or broadly obovate, sessile, yellow (rarely white or 

 red). Stamens 20 to 50 or more (rarely fewer), marginal in 2 or 3 rows upon the 

 hairy sometimes thickened base of the calyx; filaments filiform. Carpels 10 to 

 40 or more, usually numerous : styles lateral or nearly terminal, short, deciduous : 



