258 Karl M. Wiegand and Arthur J. Eames 



15. Potentilla L. 



a. Stems distinctly shrubby, diffusely branched; style clavate, lateral. 



1. P. fruticosa 

 a. Stems herbaceous. 



b. Leaves pinnate ; styles lateral or subbasal. 

 c. Calyx purple ; leaves not rugose, glaucous. 2. P. palustris 



c. Calyx green; leaves more veiny, not glaucous. 

 d. Flowers cymose; style glandular-fusiform; leaves hirsute. 



3. P. arguta 

 d. Flowers solitary; style filiform; leaves white-tomentose beneath. 



4. P. Anserina 

 b. Leaves palmate; style terminal or nearly so. 



c. Flowers cymose. 

 d. Leaflets green beneath. 

 e. Leaflets 5-9. 

 /. Petals 8-10 mm. long, exceeding the calyx, pale yellow ; stems green. 



5. P. recta 



f. Petals 3-7 mm. long, exceeding the calyx or shorter, deep yellow ; stems 

 reddish ; leaflets broader and deeper green. 5a. P. r., var. obscura 



e. Leaflets 3 ; petals shorter than the sepals, deep yellow. 



6. P. norvegica, 



var. hirsuta 

 d. Leaflets white-tomentose beneath, 5 ; petals small. 7. P. argentea 

 c. Flowers solitary along the runner-like stems. 

 d. First flower from the node above the first well-developed internode ; plant 

 small, creeping ; leaflets dull, scarcely veiny, narrowly obovate. 



8. P. pumila 

 d. First flower from the node above the second or third well-developed inter- 

 node ; plant larger, less close to the ground ; leaflets brighter green, more 

 veiny, oblanceolate. 

 e. Stems with spreading hairs. 9. P. canadensis 



c. Stems with appressed hairs, or glabrate. 9a. P. c, var. simplex 



1. P. fruticosa L. Shrubby Cinquefoil. 



Boggy meadows, in calcareous soils; scarce. June 20-Aug. 1. 



Summit Marsh, e. side (£>.) ; springy spot by railroad grade e. of Key Hill Swamp; 

 McLean Bogs, e. end (D.) ; Lake Como (Locke Pond), above the bridge (D.) ; New- 

 ton Ponds (.D.!) ; arbor vitae swamp e. of Clyde; Miller Bog, Spring Lake; Stark 

 Pond. 



Greenland and Lab. to Alaska, southw. to n. N. J., Pa., 111., Iowa, Ariz., and 

 Colo. ; rare or absent on the Atlantic Coastal Plain. Found also in Eurasia. 



2. P. palustris (L.) Scop. Marsh Cinquefoil. 



Swales and bogs, in neutral or acid waters ; infrequent. June 10-July 20. 



Cayuta Lake (D.) ; middle Round Marsh, McLean Bogs (D. !) ; Chicago Bog 

 (£).!); Lake Como (Locke Pond, D.) ; Cayuga Marshes, from Cayuga to Mon- 

 tezuma (D.) ; Vandemark Pond (D.\) ; s. of Featherbed Bog. 



Greenland and Lab. to Alaska, southw. to n. N. J., Pa., Ohio, Ind., 111., Iowa, 

 Wyo., and Calif. ; infrequent on the Atlantic Coastal Plain. Found also in Eurasia. 



At Chicago Bog all gradations are found between plants with leaves glabrous above 

 and those with a dense silky covering; also between plants of both of the above- 

 named types with densely glandular pedicels and those with no glands. The leaflets, 

 however, are all of the same shape. Therefore, in the Cayuga Lake Basin the varieties 

 of this species (see Rhodora 11:48, 1909; 12:140, 1910; and 16:5, 1914) cannot 

 be clearly defined. 



