294 NORTH AMERICAN FLORA 
Leaflets densely pubescent beneath, 
if at all tomentose, the tomen- 
.tum hidden under the long 
hairs. 
Leaves green and sparingly pu- 
bescent on the upper side. 
Leaves densely and softly pu- 
bescent on both sides, almost 
velvety ; inflorescence dense. 
Leaflets principally tomentose be- 
neath, only slightly hairy. 
Leaflets cleft more than halfway to 
the midrib into linear, oblong or 
lance-oblong divisions. 
Stems ascending or decumbent at 
the base; stem-leaves few, re- 
duced, with 3-5 leaflets. 
Stems leafy; most of the stem- 
leaves 7-foliolate. 
Plants less than 2 dm. high. 
Leaves neither tomentose nor silky, 
green. 
Stem simple, erect, few-flowered ; se- 
pals and bractlets not incurved. 
Stems spreading, with many branches; 
sepals and bractlets incurved. 
Leaves tomentose or silky, at least be- 
neath. 
Leaflets thick and coriaceous. (Mexican and 
Central American species with thick 
caudices.) 
Leaflets obovate. 
Leaves not tomentose beneath. 
Leaves tomentose beneath. 
ee linear-oblong, densely hairy on both 
sides. 
Basal leaves digitately 5-foliolate with an addi- 
tional pair of smaller leaflets on the petiole. 
Basal leaves 3-foliolate. 
Leaves more or less tomentose beneath. 
Leaves not tomentose. 
Leaflets merely toothed. 
Leaflets divided to near the base into 2 or 3 
entire segments, 
Leaves odd-pinnate. 
Style much longer than the mature achene, filiform. 
Petals from acutish to acuminate ; plant glandular- 
viscid. 
Petals rounded or emarginate at the apex. 
Leaves with 1-3 more or less approximate pairs 
of leaflets. 
Leaves not at all tomentose. 
Style subterminal. 
Style attached below the apex of the 
achene. 
Leaves more or less tomentose beneath. 
Leaves with 3-13 pairs of leaflets. 
Leaves grayish or whitish, silky or tomen- 
tose, at least beneath. 
Leaflets dissected into linear segments. 
Leaflets toothed or incised. 
Leaves green on both sides or merely 
i strigose. 
Petals yellow ; bristles of the receptacle 
not unusually long. 
Petals white ; bristles of the receptacle 
very long. 
Style not longer than the mature achene, thickened 
and glandular below (except in P. multifida) ; 
leaves usually more or less tomentose beneath. 
I. TORMENTILLAE 
Flowers 4-merous ; upper leaves 3-foliolate. 
F rowers 5-merous ; leaves usually all 5-foliolate. 
Pubescence of the stem, petioles, and peduncles appressed. 
VIII. 
XIX. 
XX. 
XXII. 
XV. 
XVI. 
XVII. 
XIv. 
XXII. 
XXIII. 
XXIV. 
XXV. 
XIX. 
XXVI. 
XXVIT. 
XXVIII. 
XXIX. 
XXX. 
Iv. 
XXXII. 
Leaflets sparingly silky or strigose, obovate, oblanceolate, or 
elliptic, toothed except at the very base. 
Leaflets crenate; bractlets ovate or elliptic, usually exceeding 
the sepals ; stem creeping. 
[VoLuME 22 
NUTTALLIANAE. % 3(9 
. PERMOLLES. 
. GRACILES. ary] 
. CANDIDAE. 
. PECTINISECTAE. *\b 
AUREAE. 
SUBVISCOSAE. 
CONCINNAE. 
SUBCORIACEAE. 
OBOVATIFOLIAE. 
HORRIDAE,. 
SUBJUGAE. 
NIVEAE. 
FRIGIDAE. 
BIFLORAE, 
SAXOSAE. 
AUREAE, 
BREVIFOLIAE. 
RUBRICAULES, 
CANDICANTES. 
LEUCOPHYLLAE. 
MULTIJUGAE. 
ARENICOLAE, 
MULTIFIDAE. 
1. P. procumbens. 
2. P. reptans. 
