352 NORTH AMERICAN FLORA [VoLUME 22 
species that agrees with this description has heen collected in later years near Hudson Bay. 
Dr. Watson adopted the name P. dissecta for P. diversifolia ehm., and has been followed 
by most American botanists. Lehmann himself regarded them as distinct and it is evident 
that P. diversifolia does not fit Pursh’s description. Neither has it been collected, so far 
as the author knows, in the vicinity of Hudson Bay. 
Potentilla fusca Schlecht. Linnaea13: 262. 1839. [P. comaroides fusca Lehm. Stirp. 
Pug. 9: 50. 1851:] This species should be closely related to P. rudrva, have digitately 
7-foliolate leaves, green and appressed-pilose above, white-tomentose beneath, and oblong 
leaflets, crenate above the middle, No species exactly answering the description has been 
seen, Hemsley (Biol. Cent. Am. 1: 376), refers it to P. haematochrus, but this does not 
agree with the description. If not a distinct species, it is rather a form of P. rubra, 
with leaflets more toothed than usually. 
Potentilla effusa gossypina Nutt.; T. & G. Fl. N. Am. 1: 437. 1840. This is still 
unknown. Dr. Hooker, in London Jour. Bot. 6: 219, states that the plant collected by 
Geyer (0. 637) was labelled by Nuttall P. gossypina. These specimens Dr. Hooker identi- 
fied as P. avachnoidea Douglas, which is P. pennsylvanica arachnoidea Lehm, There is 
no specimen in Nuttall’s herbarium at the Academy of Natural Sciences in Philadelphia, 
nor in the Torrey or the Gray herbaria. 
FPotentilla caespitosa Raf. Aut. Bot. 165. 1840. This was described as being cespitose 
and diffuse, and as having ternate leaves and petals shorter than the sepals. This accords 
best with P. Robbinsiana, but that species is unknown to the Alleghany Mountains. 
Potentilia nivalis Torr. Ann. Lyc. N. Y. 1: 32. 1824 = Acomastylis turbinata (Rydb.) 
Greene, Leaflets 1: 174. 1906 (Geum turbinatum Rydb. Bull. Torrey Club 24: 91. 1897). 
Potentitla gracilipes Piper, Bull. Torrey Club 27: 392. 1900 = Acomastylis gracilipes 
(Piper) Greene, Leaflets 1: 174, 1906, a species closely related to the last, if not identical. 
Potentilla ovalis Lehm. Delect. Sem. Hort. Hamb. 1849: 9. 1849 = Fragaria ovalis 
(Lehm.) Rydb. : 
Species of nearly all the genera of the tribe POTENTILLEAE have at some time or other 
been referred to Fotentilla, For further Potentilla synonyms, see these genera. 
21. ARGENTINA Lam. Fl. Fr. 3: 118. 1778. 
Dactylophyllum Spenn. Fl. Frib. 1084, in part. 1829. 
Perennial herbs, with slender prostrate stolons. Leaves interruptedly pinnate, with 
many leaflets. Flowers solitary in the axils of small leaves or scales on the stolons. 
Hypanthium almost flat. Bractlets, sepals, and petals normally 5, often, however, more. 
Petals yellow, broadly elliptic or almost orbicular, not at all unguiculate, obtuse, scarcely 
emarginate. Stamens 20-25, in three series, inserted closely around the base of the recep- 
tacle as in Potentilla, Filaments filiform, rather short. Anthers slightly didymous, dehis- 
cent by a longitudinal slit. Receptacle hemispheric, bearing very numerous pistils. Styles 
filiform, lateral, attached almost at the middle of the ovaries, scarcely deciduous. Mature 
achenes with thick pericarp. Seeds ascending and amphitropous. 
Type species, Potentilla Anserina \. 
Achenes corky with a deep groove; stems, petioles, and rachis of the leaves densely pubescent, 
with at first ascending and later spreading hairs. 
Leaves silvery on both sides. 1. A. argentiea. 
Leaves green and glabrate above. 2. A, Anserina. 
Achenes not corky, without a groove; stem, petioles, and the rachis of the 
leaves glabrous or slightly appressed-hairy and glabrate. 
Petals usually over 1 cm. long, rounded-obovate. 
Bractlets lanceolate, longer than the sepals ; leaves usually 3-4 dm. long. 3. 4. pacifica. 
Bractlets elliptic or oblong, shorter than the sepals ; leaves 1-2 dm. long. 4. A. occidentalis. 
Petals 6-8 mm., rarely 1 cm. long, usually elliptic-obovate. 
Leaflets elliptic-obovate to oblanceolate, many-toothed, silky as well as 
tomentose beneath; bractlets nearly equaling the sepals or even 
exceeding them. : 
Upper leaflets rounded at the apex, with more than 20 linear-lanceolate 
teeth ; petals elliptic, about 6 mm. long; pistils few. 5. A, Babcockiana.. 
Upper leafiets acute or obtuse at the apex, with less than 20 triangular- 
lanceolate or ovate-lanceolate teeth. 
