Key 2

1	Cauline leaves absent.		(2)
+	Cauline leaves 1-3 or more.		(3)
2 (1)	Petals yellow, emarginate or 2-lobulate at apex; leaf blade with 3-5 parallel veins; staminodes 3-lobed for ca. 1/3 their length, lobes equal, narrow		15 P. lutea
+	Petals white, rounded-obtuse at apex; leaf blade usually with 5 parallel veins; staminodes 3-lobed for ca. 1/5 their length, central lobe longer than lateral ones		16 P. scaposa
3 (1)	Cauline leaves 2 or 3 or more.		(4)
+	Cauline leaf 1.		(9)
4 (3)	Cauline leaves 2; staminodes 2- or 3-lobed and eglandular at apex.		(5)
+	Cauline leaves 3 or more; staminodes branched, branches with globose glands at apex.		(6)
5 (4)	Staminodes 2-lobed at apex; stem 10-50 cm		46 P. bifolia
+	Staminodes 3-lobed at apex; stem 4-6 cm		42 P. lijiangensis
6 (4)	Petals rhomboid, margin subentire or undulate		53 P. rhombipetala
+	Petals not rhomboid, margin fimbriate proximally or throughout.		(7)
7 (6)	Petal margin fimbriate proximally		54 P. amoena
+	Petal margin fimbriate throughout.		(8)
8 (7)	Petals oblanceolate or oblong, marginal fimbriae turgid at apex; staminode branches not parallel; cauline leaves usually 2-5		55 P. noemiae
+	Petals ovate or triangular-ovate, marginal fimbriae not turgid at apex; staminode branches parallel; cauline leaves usually more than 3		56 P. foliosa
9 (3)	Basal leaves 10 or more, cespitose.		(10)
+	Basal leaves usually 3-5(-12), not cespitose.		(13)
10 (9)	Staminodes entire and rounded at apex.		(11)
+	Staminodes 2-lobed and 2-labiate at apex.		(12)
11 (10)	Petals broadly elliptic; sepals oblong; cauline leaf borne near middle of stem		9 P. petitmenginii
+	Petals broadly oblanceolate; sepals lanceolate; cauline leaf borne near apex of stem		10 P. esquirolii
12 (10)	Basal leaf blade broadly obovate, broadly ovate, or broadly rhomboid-ovate, 6-15 mm		11 P. faberi
+	Basal leaf blade rhomboid, ovate-rhomboid, or suborbicular, 2-3 mm		12 P. labiata
13 (9)	Anther connective apically projected into a lanceolate appendage.		(14)
+	Anther connective not apically projected.		(16)
14 (13)	Basal leaf blade ovate-cordate or ovate; staminodes 3-lobed for 1/4-1/3 their length, central lobe narrow, lateral ones wider; style short, not exserted beyond staminodes, occasionally longer		43 P. brevistyla
+	Basal leaf blade reniform or suborbicular; staminodes 3-lobed for 1/2 their length or slightly more; style usually longer, exserted beyond staminodes, rarely shorter.		(15)
15 (14)	Staminodes divided for 2/5-1/2 their length; basal leaf blade reniform or suborbicular		44 P. delavayi
+	Staminodes divided for ca. 2/3 their length; basal leaf blade reniform		45 P. leptophylla
16 (13)	Basal leaf blade elliptic, obovate, or broadly orbicular.		(17)
+	Basal leaf blade reniform, ovate-reniform, or ovate-cordate.		(21)
17 (16)	Basal leaf blade elliptic or ovate.		(18)
+	Basal leaf blade obovate or broadly orbicular.		(19)
18 (17)	Basal leaf blade elliptic, rarely obovate-elliptic; staminodes 3-cleft at apex		24 P. xinganensis
+	Basal leaf blade ovate or oblong-ovate; staminodes 5-branched, branches globose glandular at apex		57 P. guilinensis
19 (17)	Basal leaf blade densely purple-brown punctate, broadly orbicular, apex emarginate		60 P. longshengensis
+	Basal leaf blade not punctate, obovate, oblong-obovate, broadly orbicular, or suborbicular.		(20)
20 (19)	Basal leaf blade obovate or oblong-obovate, 2-4 × 1.5-2.6 cm; staminodes 3- or 4(or 5)-lobed for ca. 1/3 their length		41 P. obovata
+	Basal leaf blade broadly orbicular or suborbicular, 1.2-2 × 1.4-2.5 cm; staminodes (3 or)4- or 5-lobed for 1/3-1/2 their length		48 P. dilatata
21 (16)	Staminodes terete, entire, apex rounded or discoid.		(22)
+	Staminodes branched, or flat with apex dentate or lobed.		(29)
22 (21)	Basal leaf blade reniform, base deeply cordate; petals green.		(23)
+	Basal leaf blade ovate-cordate, base cordate; petals white or green.		(24)
23 (22)	Stem 15-30 cm; petals lanceolate or oblong-lanceolate, 10-20 × ca. 5 mm; basal leaf blade 3-6 × 5-9.5 cm		1 P. longipetala
+	Stem 5-11 cm; petals flabellate, 4-8 × 3-6 mm; basal leaf blade 5-25 × 13-30 mm		2 P. tenella
24 (22)	Petals green or yellow-green.		(25)
+	Petals white or yellowish.		(27)
25 (24)	Petals yellow-green; cauline leaf ovate-reniform; basal leaf blade ovate-reniform; staminodes indistinctly 3-6-dentate at apex		5 P. longipetaloides
+	Petals green; cauline leaf oblong or ovate-lanceolate; basal leaf blade ovate-cordate or ovate-reniform.		(26)
26 (25)	Petals densely purple-brown punctate; staminodes rounded at apex; basal leaf blade usually ovate-cordate		3 P. angustipetala
+	Petals not punctate; staminodes truncate or emarginate at apex; basal leaf blade usually ovate-reniform		4 P. yulongshanensis
27 (24)	Petals distinctly purple-brown punctate, obovate-oblong, often emarginate at apex; staminodes often indistinctly 3-crenate at apex, or entire		6 P. yunnanensis
+	Petals indistinctly purple punctate, oblong or narrowly oblanceolate, acute or rounded at apex; staminodes rounded at apex.		(28)
28 (27)	Basal leaf blade ovate-cordate, base cordate; cauline leaf borne near apex of stem, much smaller than basal leaves; petals yellowish		7 P. yanyuanensis
+	Basal leaf blade ovate-triangular, base not cordate; cauline leaf borne near base of stem, about as large as basal leaves; petals white		8 P. humilis
29 (21)	Staminodes branched.		(30)
+	Staminodes flat, apex dentate or lobed.		(34)
30 (29)	Staminodes 7-23-branched		63 P. palustris
+	Staminodes (3 or)5(or 7)-branched.		(31)
31 (30)	Petal margin fimbriate proximally, entire or undulate distally.		(32)
+	Petal margin fimbriate throughout; staminodes divided for 1/3-1/2 their length.		(33)
32 (31)	Staminodes divided almost to base		58 P. gansuensis
+	Staminodes divided for ca. 1/2 their length		59 P. simaoensis
33 (31)	Basal leaf blade ovate-cordate, thick textured, base cordate		61 P. perciliata
+	Basal leaf blade reniform, thin textured, base subcordate or truncate		62 P. davidii
34 (29)	Staminodes (3-)5-7-dentate at apex.		(35)
+	Staminodes 3- or 5-lobed at apex.		(37)
35 (34)	Cauline leaf borne near base of stem		22 P. qinghaiensis
+	Cauline leaf borne near middle of stem or distally.		(36)
36 (35)	Petals broadly spatulate or obovate, base broadly and shortly clawed (claw ca. 1 mm), margin erose or subentire; basal leaf blade cuneate or subcordate at base		13 P. degeensis
+	Petals triangular-ovate, base long clawed (claw 2-2.5 mm), margin long fimbriate proximally; basal leaf blade deeply cordate at base		14 P. farreri
37 (34)	Staminodes 5-lobed at apex.		(38)
+	Staminodes 3-lobed at apex.		(42)
38 (37)	Petal margin sparsely and shortly fimbriate throughout; stem less than 10 cm		52 P. omeiensis
+	Petal margin long fimbriate proximally; stem more than 10 cm.		(39)
39 (38)	Staminode lobes subequal.		(40)
+	Staminode lobes unequal.		(41)
40 (39)	Basal leaf blade broadly cordate, about as long as wide, 2.5-4.5(-5) × 3.8-5.5 cm; petals shortly clawed		47 P. wightiana
+	Basal leaf blade oblong-cordate, nearly 2 × as long as wide, to 7 cm; petals long clawed		49 P. monochoriifolia
41 (39)	Central 3 staminode lobes ca. 3 × as long as lateral ones; petals yellow-white; basal leaf blade reniform		50 P. yiliangensis
+	Staminode lobes subequal, central 3 parted, lateral ones very shallowly lobed; petals white; basal leaf blade ovate-cordate		51 P. chengkouensis
42 (37)	Staminode lobes unequal.		(43)
+	Staminode lobes subequal.		(44)
43 (42)	Central staminode lobe much shorter than lateral ones; petals greenish, narrowly oblong, margin sparsely and shortly fimbriate; cauline leaf borne distally on stem		39 P. cooperi
+	Central staminode lobe ca. 0.6 mm longer than lateral ones; petals white, obovate, rarely subspatulate, margin entire; cauline leaf borne near base of stem		40 P. laxmannii
44 (42)	Petal margin long fimbriate proximally.		(45)
+	Petal margin shortly fimbriate or erose proximally, or entire.		(47)
45 (44)	Basal leaf blade ovate-cordate, larger, thick textured		19 P. crassifolia
+	Basal leaf blade reniform, orbicular, or broadly ovate-orbicular, occasionally ovate-cordate, thin textured.		(46)
46 (45)	Petals oblanceolate, with 2 green, oblong glands near base, apex acute; basal leaf blade 1.2-2.4 × 1.2-2.4 cm, much larger than cauline leaf		17 P. yui
+	Petals broadly obovate, eglandular, apex emarginate; basal leaf blade 6-11 × 7.5-14 mm, subequaling cauline leaf		18 P. chinensis
47 (44)	Petal margin shortly fimbriate proximally.		(48)
+	Petal margin erose or entire.		(49)
48 (47)	Sepals and petals purple-brown punctate; petals 5-6 × 3-4 mm; basal leaf blade 9-10 × 8-9 mm		21 P. venusta
+	Sepals and petals not punctate; petals 7.8-9.5 × 5.2-6.1 mm; basal leaf blade 1-1.5 cm × 9-14 mm		20 P. epunctulata
49 (47)	Ovary superior.		(50)
+	Ovary semi-inferior.		(55)
50 (49)	Basal leaf blade broadly elliptic, attenuate into petiole at base; petals yellow, spatulate or spatulate-oblanceolate		23 P. filchneri
+	Basal leaf blade ovate-reniform or ovate-cordate, cordate at base; petals white or green, obovate or lanceolate.		(51)
51 (50)	Petals green, minutely purple punctate, lanceolate, margin densely erose, apex acuminate		25 P. lanceolata
+	Petals white, obovate, margin sparsely erose or entire, apex rounded or 2-lobed.		(52)
52 (51)	Basal leaf blade ovate-reniform; stem to 4 cm		26 P. kangdingensis
+	Basal leaf blade ovate-cordate; stem usually more than 4 cm.		(53)
53 (52)	Petals 2-lobed or emarginate at apex; staminodes 3-lobed for ca. 1/3 their length		27 P. mysorensis
+	Petals rounded at apex; staminodes shallowly 3(-6)-lobed for ca. 1/6 their length.		(54)
54 (53)	Stem 7-10 cm; basal leaf blade densely brown punctate, ovate, with 5-7 arcuate veins, base cordate; staminode lobes rounded at apex, subequal		29 P. cacuminum
+	Stem 16-27 cm; basal leaf blade not distinctly punctate, ovate-oblong, 7-9-veined, base deeply cordate; staminode lobes truncate at apex, central one narrower than lateral ones		28 P. submysorensis
55 (49)	Basal leaf blade ovate-cordate or reniform.		(56)
+	Basal leaf blade ovate-oblong.		(58)
56 (55)	Basal leaf blade ovate-cordate or reniform, longer than wide base cordate		31 P. pusilla
+	Basal leaf blade ovate-cordate, about as long as wide, base deeply cordate.		(57)
57 (56)	Stem 8-13 cm; basal leaf blade 5-15 × 7-15 mm, cordate or subcordate at base		27 P. mysorensis
+	Stem 23-32 cm; basal leaf blade 3-4.1 × 3-4.1 cm, deeply cordate at base		30 P. cordata
58 (55)	Stem (13-)17-40 cm; basal leaf blade ovate-oblong or ovate-triangular, truncate, subcordate, or sometimes decurrent at base.		(59)
+	Stem 6-21 cm; basal leaf blade ovate-cordate, not truncate at base.		(61)
59 (58)	Staminode lamina 3-parted for (1/2-)2/3 its length		32 P. oreophila
+	Staminode lamina 3-lobed for 1/5-1/4(-1/2) its length.		(60)
60 (59)	Staminodes ca. 3.2 mm, lobes shortly linear; petals yellow		33 P. tibetana
+	Staminodes 4-5 mm, lobes lanceolate or ovate-lanceolate; petals white		34 P. nubicola
61 (58)	Petals obovate or broadly so.		(62)
+	Petals lanceolate or oblong-lanceolate.		(63)
62 (61)	Petals purple punctate, broadly obovate; stem less than 6 cm; basal leaf petiole ca. 1 cm, leaf blade usually cordate at base		35 P. subscaposa
+	Petals not or indistinctly punctate, obovate; stem 8-21 cm, rarely shorter; basal leaf petiole (1.5-)3.5-6 cm, leaf blade usually truncate at base		36 P. deqenensis
63 (61)	Petals white; basal leaf petiole 8-15 mm, occasionally to 4 cm		37 P. trinervis
+	Petals green; basal leaf petiole (1-)5-25 mm		38 P. viridiflora