Chromosome numbers of Taraxacum plants
The chromosome numbers of the 18 dandelion species distributed in Northeast China (including the seven previously published species) were 16, 24, and 32 for diploid, triploid, and tetraploid germplasm resources, respectively. Chromosome maps and karyotype analysis revealed two composition types of chromosomes, the metacentric (m) and submetacentric (sm).
Karyotype analysis of 18 Taraxacum species
We described the karyotype characteristics of 11 Taraxacum species and combined these with the karyotype characteristics of the seven Taraxacum species previously reported by Ning (2012). In addition, by comparing with the plant chromosome number indexes and the CCDB, we found that karyotype information was recorded for the first time for the following 11 species: T. antungense, T. urbanum, T. variegatum, T. asiaticum var. lonchophyllum, T. liaotungense, T. pingue, T. heterolepis, T. brassicifolium, T. falcilobum, T. junpeianum, and T. erythropodium. The previously reported chromosome numbers of T. asiaticum Dahlst. (16 chromosomes), T. ohwianum Kitam. (24 chromosomes), and T. platypecidum Diels (12 chromosomes) differed from those observed in this study (24, 16, and 24 chromosomes, respectively). Hence, we recorded these new counts in the CCDB.
Table.2. The chromosome parameters of 11 Taraxacum
No
|
T. mongolicum Hand. -Mazz.
|
T. liaotungense Kitag. in Bot.
|
1
|
Relative length (%)
|
CI
(%)
|
AR
|
CP
|
Relative length (%)
|
CI
(%)
|
AR
|
CP
|
LL
|
SL
|
TL
|
LL
|
SL
|
TL
|
15.80
|
14.76
|
15.16
|
40.67
|
1.45
|
m
|
16.07
|
14.52
|
15.58
|
35.86
|
1.78
|
sm
|
2
|
13.88
|
14.73
|
14.40
|
37.62
|
1.65
|
m
|
14.45
|
15.50
|
14.95
|
39.90
|
1.50
|
m
|
3
|
13.15
|
14.43
|
13.93
|
36.84
|
1.71
|
sm
|
14.59
|
14.12
|
14.51
|
37.47
|
1.66
|
m
|
4
|
11.55
|
12.04
|
11.85
|
38.07
|
1.62
|
m
|
12.20
|
13.62
|
12.83
|
40.86
|
1.24
|
m
|
5
|
12.73
|
11.07
|
11.72
|
42.41
|
1.35
|
m
|
11.89
|
12.14
|
11.41
|
40.97
|
1.44
|
m
|
6
|
12.80
|
10.33
|
11.29
|
44.25
|
1.25
|
m
|
10.63
|
11.18
|
10.91
|
39.44
|
1.53
|
m
|
7
|
9.70
|
11.95
|
11.07
|
34.20
|
1.92
|
sm
|
10.52
|
9.55
|
10.21
|
35.96
|
1.98
|
sm
|
8
|
10.34
|
10.65
|
10.53
|
38.34
|
1.60
|
m
|
9.60
|
9.32
|
9.56
|
37.53
|
1.66
|
m
|
No
|
T. coreanum Nakai.
|
T. formosanum Kitam.
|
1
|
Relative length (%)
|
CI
(%)
|
AR
|
CP
|
Relative length (%)
|
CI
(%)
|
AR
|
CP
|
LL
|
SL
|
TL
|
LL
|
SL
|
TL
|
17.43
|
13.55
|
15.87
|
34.32
|
1.91
|
sm
|
15.17
|
13.63
|
14.59
|
35.73
|
1.79
|
sm
|
2
|
12.95
|
14.45
|
13.55
|
42.84
|
1.33
|
m
|
12.52
|
14.19
|
13.91
|
38.98
|
1.56
|
m
|
3
|
12.38
|
12.73
|
12.52
|
40.86
|
1.44
|
m
|
13.85
|
13.54
|
13.73
|
37.68
|
1.65
|
m
|
4
|
12.08
|
11.83
|
11.98
|
39.69
|
1.52
|
m
|
12.05
|
13.90
|
12.76
|
41.64
|
1.40
|
m
|
5
|
11.16
|
13.18
|
11.97
|
44.24
|
1.26
|
m
|
11.86
|
11.44
|
11.70
|
37.38
|
1.67
|
m
|
6
|
11.99
|
12.90
|
12.36
|
41.94
|
1.38
|
m
|
11.47
|
12.08
|
11.70
|
39.44
|
1.53
|
m
|
7
|
10.95
|
12.43
|
11.55
|
43.28
|
1.31
|
m
|
11.99
|
9.89
|
11.19
|
33.78
|
1.95
|
sm
|
8
|
11.02
|
8.89
|
10.17
|
35.15
|
1.84
|
sm
|
9.84
|
11.30
|
10.40
|
41.53
|
1.40
|
m
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
No
|
T. sinomongolicum Kitag.
|
T. heterolepis Nakai et Koidz.ex Kitag.
|
1
|
Relative length (%)
|
CI
(%)
|
AR
|
CP
|
Relative length (%)
|
CI
(%)
|
AR
|
CP
|
LL
|
SL
|
TL
|
LL
|
SL
|
TL
|
10.34
|
10.11
|
10.22
|
35.23
|
1.24
|
m
|
10.21
|
10.02
|
10.11
|
34.65
|
1.55
|
m
|
2
|
11.12
|
10.97
|
11.04
|
37.61
|
1.26
|
m
|
11.69
|
10.39
|
11.04
|
39.23
|
1.94
|
sm
|
3
|
11.87
|
11.46
|
11.66
|
38.48
|
1.32
|
m
|
12.37
|
12.12
|
12.24
|
37.18
|
2.11
|
sm
|
4
|
13.18
|
13.12
|
13.15
|
37.74
|
1.78
|
sm
|
13.26
|
12.56
|
12.91
|
40.24
|
2.31
|
sm
|
5
|
12.43
|
12.17
|
12.32
|
40.14
|
1.26
|
m
|
13.78
|
14.38
|
14.08
|
40.97
|
1.52
|
m
|
6
|
12.64
|
12.93
|
12.78
|
41.37
|
1.49
|
m
|
14.43
|
15.21
|
14.82
|
39.44
|
1.87
|
sm
|
7
|
13.78*
|
14.36*
|
14.07
|
38.18
|
1.79
|
sm*
|
15.08*
|
16.31*
|
15.69
|
35.96
|
1.68
|
m*
|
8
|
14.64
|
14.88
|
14.76
|
35.64
|
1.82
|
sm
|
9.18
|
9.01
|
9.09
|
37.53
|
1.11
|
m
|
No
|
T.brassicae folium Kitag.
|
T. platypecidum Diels.
|
1
|
Relative length (%)
|
CI
(%)
|
AR
|
CP
|
Relative length (%)
|
CI
(%)
|
AR
|
CP
|
LL
|
SL
|
TL
|
LL
|
SL
|
TL
|
10.43
|
10.14
|
10.28
|
32.38
|
1.41
|
m
|
9.11
|
8.69
|
8.9
|
34.16
|
1.24
|
m
|
2
|
11.86
|
12.13
|
11.99
|
37.81
|
1.66
|
m
|
10.01
|
10.97
|
10.49
|
38.39
|
1.74
|
sm
|
3
|
12.45
|
13.39
|
12.92
|
38.45
|
2.28
|
sm
|
11.57*
|
11.94*
|
11.75
|
35.38
|
2.15
|
sm*
|
4
|
10.98
|
10.67
|
10.82
|
36.54
|
1.24
|
m
|
12.21
|
12.73
|
12.47
|
36.24
|
1.78
|
sm
|
5
|
11.27
|
11.68
|
11.47
|
40.26
|
1.29
|
m
|
13.06
|
13.15
|
13.11
|
38.72
|
1.97
|
sm
|
6
|
13.67
|
13.67
|
13.67
|
44.21
|
2.89
|
sm
|
13.94
|
13.68
|
13.81
|
36.92
|
2.53
|
sm
|
7
|
14.45
|
13.95
|
14.20
|
41.32
|
2.18
|
sm
|
14.69
|
14.26
|
14.48
|
40.19
|
1.72
|
sm
|
8
|
14.87*
|
14.37*
|
14.62
|
35.31
|
1.82
|
sm*
|
15.41
|
14.58
|
14.99
|
39.33
|
2.24
|
sm
|
No
|
T. falcilobum Kitag.
|
T. borealisinense Kitam.
|
1
|
Relative length (%)
|
CI
(%)
|
AR
|
CP
|
Relative length (%)
|
CI
(%)
|
AR
|
CP
|
LL
|
SL
|
TL
|
LL
|
SL
|
TL
|
10.06
|
9.87
|
9.97
|
32.67
|
1.21
|
m
|
9.16
|
9.01
|
9.08
|
33.86
|
1.63
|
m
|
2
|
10.98*
|
10.91*
|
10.95
|
35.12
|
1.86
|
sm*
|
13.94
|
13.61
|
13.77
|
42.91
|
1.54
|
m
|
3
|
11.42
|
11.47
|
11.45
|
36.48
|
1.63
|
m
|
10.98*
|
11.42*
|
11.2
|
37.47
|
2.16
|
m*
|
4
|
12.37
|
12.59
|
12.48
|
39.08
|
1.91
|
sm
|
12.02
|
12.43
|
12.23
|
40.86
|
1.48
|
m
|
5
|
12.68
|
13.28
|
12.98
|
40.43
|
1.86
|
sm
|
13.29
|
12.85
|
13.07
|
40.25
|
2.44
|
sm
|
6
|
13.53
|
13.52
|
13.52
|
42.26
|
1.83
|
sm
|
10.13
|
10.25
|
10.19
|
32.24
|
1.53
|
m
|
7
|
14.32
|
14.09
|
14.20
|
43.27
|
1.79
|
sm
|
14.56
|
14.92
|
14.74
|
42.36
|
1.78
|
sm
|
8
|
14.64
|
14.27
|
14.45
|
45.14
|
1.93
|
sm
|
15.92
|
15.51
|
15.71
|
45.13
|
1.92
|
sm
|
No
|
T. erythopodium Kitag.
|
|
1
|
Relative length (%)
|
CI
(%)
|
AR
|
CP
|
|
LL
|
SL
|
TL
|
|
10.13
|
10.25
|
10.19
|
38.13
|
2.27
|
sm
|
|
2
|
11.27
|
11.55
|
11.41
|
40.25
|
2.05
|
sm
|
|
3
|
12.16
|
11.43
|
11.79
|
38.22
|
1.96
|
sm
|
|
4
|
13.74
|
12.42
|
13.08
|
37.68
|
1.87
|
sm
|
|
5
|
13.89
|
14.26
|
14.08
|
42.22
|
1.61
|
m
|
|
6
|
14.54
|
15.74
|
15.14
|
41.79
|
1.73
|
sm
|
|
7
|
14.15*
|
15.64*
|
14.89
|
38.42
|
1.31
|
m*
|
|
8
|
10.12
|
8.71
|
9.42
|
34.31
|
1.98
|
sm
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Resource: LL: long arm length; SL: short arm length; TL: total length; CI: centromeric index; AR: arm ratio; CP: position of centromere; *Chromosome with satellite, whose length was not included in the chromosome length.
Table.3. Karyotype comparison of 18 Taraxacum
Species
|
A.A.R
|
Lt/St
|
P.C.A
|
As.k
(%)
|
Karyotype
|
Satellite number
|
Karyotype formula
|
T. antungense Kitag.
|
1.61
|
1.54
|
0
|
61.32%
|
1A
|
3
|
2n = 3x = 12 m + 3 sm(3SAT) + 9sm
|
T. asiaticum Dahlst.
|
1.50
|
2.03
|
12.5
|
59.98%
|
1A
|
3
|
2n = 3x = 3m (3SAT) + 18 m + 3 sm
|
T. urbanum Kitag.
|
1.61
|
1.65
|
0
|
61.43%
|
1A
|
3
|
2n = 3x = 12 m + 3 sm(3SAT) + 9sm
|
T. ohwianum Kitag.
|
1.78
|
1.82
|
0.25
|
63.81%
|
2A
|
3
|
2n = 2x= 2m(SAT) + 6m + 8sm
|
T. variegatum Kitag.
|
1.78
|
1.62
|
0.37
|
64.02%
|
2A
|
0
|
2n =4x = 12m + 20sm
|
T. asiaticum var.
lonchophyllum Kitag.
|
1.49
|
1.62
|
0
|
59.68%
|
1A
|
3
|
2n = 3x = 3m(3SAT) + 18 m + 3 sm
|
T. junpeianum Kitam. In Act.
|
1.70
|
1.49
|
0.25
|
61.63%
|
2A
|
3
|
2n = 3x = 3m(SAT) + 9m + 12sm
|
T. mongolicum Hand.-Mazz.
|
1.56
|
1.43
|
0
|
66.96%
|
1A
|
0
|
2n = 4x = 24m + 8sm
|
T. liaotungense Kitag.
|
1.59
|
1.59
|
0
|
64.17%
|
1A
|
0
|
2n = 4x = 24m + 8sm
|
T. coreanum Nakai
|
1.49
|
1.56
|
0
|
59.80%
|
1A
|
0
|
2n = 4x = 24m + 8sm
|
T. formosanum Kitam.
|
1.61
|
1.40
|
0
|
62.77%
|
1A
|
0
|
2n = 4x = 24m + 8sm
|
T. sinomongolicum Kitag.
|
1.49
|
1.83
|
0
|
60.18%
|
1A
|
3
|
2n = 3x = 15m + 6sm+3sm(3SAT)
|
T. heterolepis Nakai et Koidz. ex Kitag.
|
1.76
|
2.41
|
0.25
|
67.34%
|
2B
|
3
|
2n = 3x = 9m +3m (3SAT)+ 9sm
|
T. brassicae folium Kitag.
|
1.85
|
1.97
|
0.37
|
65.32%
|
2A
|
3
|
2n = 3x = 9m +3m (3SAT)+ 9sm
|
T. platypecidum Diels
|
1.92
|
2.14
|
0.37
|
66.41%
|
2B
|
3
|
2n = 3x = 3m +3sm(3SAT) +18sm
|
T. falcilobum Kitag.
|
1.75
|
2.27
|
0
|
61.18%
|
1B
|
3
|
2n = 3x = 6m +3sm(3SAT) +15sm
|
T. borealisinense Kitam.
|
1.81
|
2.49
|
0.25
|
61.67%
|
2A
|
3
|
2n = 3x = 9m +3sm(3SAT) +12sm
|
T. erythopodium Kitag.
|
1.84
|
2.18
|
0.25
|
67.45%
|
2B
|
3
|
2n = 3x = 3m(SAT) + 3m + 18sm
|
|
|
|
|
|
|
|
|
|
Resource: A.A.R: average arm ratio; Lt/St: ratio of the longest chromosome to the shortest; P.C.A: ratio of long arms to short arms is greater than 2; As.k(%): karyotype asymmetry coefficient.
T. mongolicum Hand.-Mazz.
The chromosome number for this species was 2n = 4x = 32. The karyotype formula was K(2n) = 4x = 24 m + 8 sm. The absolute length varied between 16.32 to 25.83 μm. The arm ratio varied between 1.25 to 1.92, and the average arm ratio was 1.56. The longest: shortest chromosome ratio was 1.43. None of the chromosomes had an arm ratio greater than 2. The karyotype asymmetry coefficient was 66.96%, which corresponds to 1A karyotype. Satellite chromosomes were absent. The 3 and 7 pairs of chromosomes were of sm type, and the remaining six pairs were of m type. The morphological characteristics of the chromosomes are shown in Table 2 and Figs. 2 and 3.
T. liaotungense Kitag.
The chromosome number for this species was 2n = 4x = 32. The karyotype formula was K(2n) = 4x = 24 m + 8 sm. The absolute length varied between 16.78 to 25.21 μm. The arm ratio varied between 1.24 to 1.98, and the average arm ratio was 1.59. The longest: shortest chromosome ratio was 1.59. None of the chromosomes had an arm ratio greater than 2. The karyotype asymmetry coefficient was 64.17%, which corresponds to 1A karyotype. Satellite chromosomes were absent. The 1 and 8 pair of chromosomes was of sm type, and the remaining six pairs were of m type. The morphological characteristics of the chromosomes are shown in Table 2 and Figs. 2 and 3.
T. coreanum Nakai.
The chromosome number for this species was 2n = 4x = 32. The karyotype formula was K(2n) = 4x = 24 m + 8 sm. The absolute length varied between 18.56 to 28.32 μm. The arm ratio varied between 1.31 to 1.91, and the average arm ratio was 1.49. The longest: shortest chromosome ratio was 1.56. None of the chromosomes had an arm ratio greater than 2. The karyotype asymmetry coefficient was 59.80%, which corresponds to 1A karyotype. Satellite chromosomes were absent. The 1 and 7 pair of chromosomes was of sm type, and the remaining six pairs were of m type. The morphological characteristics of the chromosomes are shown in Table 2 and Figs. 2 and 3.
T. formosanum Kitam.
The chromosome number for this species was 2n = 4x = 32. The karyotype formula was K(2n) = 4x = 24 m + 8 sm. The absolute length varied between 17.21 to 27.64 μm. The arm ratio varied between 1.40 to 1.95, and the average arm ratio was 1.61. The longest: shortest chromosome ratio was 1.40. None of the chromosomes had an arm ratio greater than 2. The karyotype asymmetry coefficient was 62.77%, which corresponds to 1A karyotype. Satellite chromosomes were absent. The 1 and 7 pair of chromosomes was of sm type, and the remaining six pairs were of m type. The morphological characteristics of the chromosomes are shown in Table 2 and Figs. 2 and 3.
T. sinomongolicum Kitag.
The chromosome number for this species was 2n = 3x = 24. The karyotype formula was K(2n) = 3x = 15m + 6sm + 3sm (3SAT). The absolute length varied between 6.32 to 9.24 μm. The arm ratio varied between 1.24 to 1.82, and the average arm ratio was 1.49. The longest: shortest chromosome ratio was 1.83. None of the chromosomes had an arm ratio greater than 2. The karyotype asymmetry coefficient was 60.18%, which corresponds to 1A karyotype. Satellite chromosomes were absent. Among them, chromosome 7 has a satellite chromosome (SAT),the 4, 7, 8 pair of chromosomes was of sm type, and the remaining five pairs were of m type. The morphological characteristics of the chromosomes are shown in Table 2 and Figs. 2 and 3.
T. heterolepis Nakai et Koidz.ex Kitag.
The chromosome number for this species was 2n = 3x = 24. The karyotype formula was K(2n) = 3x = 9m +3m (3SAT) + 9sm. The absolute length varied between 6.25 to 9.56 μm. The arm ratio varied between 1.11 to 2.31, and the average arm ratio was 1.76. The longest: shortest chromosome ratio was 2.41. The chromosomes had an arm ratio greater than 2 ratio 25%. The karyotype asymmetry coefficient was 67.34%, which corresponds to 2B karyotype. Satellite chromosomes were absent. Among them, chromosome 7 has a satellite chromosome (SAT),the 2, 3, 4, 6 pair of chromosomes was of sm type, and the remaining four pairs were of m type. The morphological characteristics of the chromosomes are shown in Table 2 and Figs. 2 and 3.
T. brassicae folium Kitag.
The chromosome number for this species was 2n = 3x = 24. The karyotype formula was K(2n) = 3x = 9m +3m (3SAT) + 9sm. The absolute length varied between 4.97 to 9.32 μm. The arm ratio varied between 1.24 to 2.98, and the average arm ratio was 1.85. The longest: shortest chromosome ratio was 1.97. The chromosomes had an arm ratio greater than 2 ratio 37%. The karyotype asymmetry coefficient was 65.32%, which corresponds to 2A karyotype. Satellite chromosomes were absent. Among them, chromosome 8 has a satellite chromosome (SAT),the 1, 2, 4, 5 pair of chromosomes was of m type, and the remaining four pairs were of sm type. The morphological characteristics of the chromosomes are shown in Table 2 and Figs. 2 and 3.
T. platypecidum Diels.
The chromosome number for this species was 2n = 3x = 24. The karyotype formula was K(2n) = 3x = 3m +3sm (3SAT) +18sm. The absolute length varied between 5.27 to 10.67 μm. The arm ratio varied between 1.24 to 2.53, and the average arm ratio was 1.92. The longest: shortest chromosome ratio was 2.14. The chromosomes had an arm ratio greater than 2 ratio 37%. The karyotype asymmetry coefficient was 66.41%, which corresponds to 2B karyotype. Satellite chromosomes were absent. Among them, chromosome 3 has a satellite chromosome (SAT),the 1 pair of chromosomes was of m type, and the remaining seven pairs were of sm type. The morphological characteristics of the chromosomes are shown in Table 2 and Figs. 2 and 3.
T. falcilobum Kitag.
The chromosome number for this species was 2n = 3x = 24. The karyotype formula was K(2n) = 3x = 6m +3sm (3SAT) +15sm. The absolute length varied between 6.25 to 12.47 μm. The arm ratio varied between 1.21 to 1.93, and the average arm ratio was 1.75. The longest: shortest chromosome ratio was 2.27. None of the chromosomes had an arm ratio greater than 2. The karyotype asymmetry coefficient was 61.18%, which corresponds to 1B karyotype. Satellite chromosomes were absent. Among them, chromosome 2 has a satellite chromosome (SAT),the 1, 3 pair of chromosomes was of m type, and the remaining six pairs were of sm type. The morphological characteristics of the chromosomes are shown in Table 2 and Figs. 2 and 3.
T. borealisinense Kitam.
The chromosome number for this species was 2n = 3x = 24. The karyotype formula was K(2n) = 3x = 9m +3sm (3SAT) +12sm. The absolute length varied between 6.00 to 10.68 μm. The arm ratio varied between 1.53 to 2.44, and the average arm ratio was 1.81. The longest: shortest chromosome ratio was 2.49. The chromosomes had an arm ratio greater than 2 ratio 25%. The karyotype asymmetry coefficient was 61.63%, which corresponds to 2A karyotype. Satellite chromosomes were absent. Among them, chromosome 3 has a satellite chromosome (SAT),the 5, 7, 8 pair of chromosomes was of sm type, and the remaining five pairs were of m type. The morphological characteristics of the chromosomes are shown in Table 2 and Figs. 2 and 3.
T. erythopodium Kitag.
The chromosome number for this species was 2n = 3x = 24. The karyotype formula was K(2n) = 3x = 3m (SAT) + 3m + 18sm. The absolute length varied between 5.27 to 8.69 μm. The arm ratio varied between 1.31 to 2.27, and the average arm ratio was 1.84. The longest: shortest chromosome ratio was 2.18. The chromosomes had an arm ratio greater than 2 ratio 25%. The karyotype asymmetry coefficient was 67.45%, which corresponds to 2B karyotype. Satellite chromosomes were absent. Among them, chromosome 7 has a satellite chromosome (SAT),the 5, 7 pair of chromosomes was of m type, and the remaining six pairs were of sm type. The morphological characteristics of the chromosomes are shown in Table 2 and Figs. 2 and 3.
PCA of karyotype-related data
The karyotype indexes obtained by karyotype analysis of the 18 species were subjected to PCA. We found that the relative total length, relative long arm length, and relative short arm length of the chromosomes formed principal component (PC) 1. In other words, the size of chromosomes was the main factor for interspecific classification. The kinetochore index, percentage with arm ratio greater than 2, and average arm ratio contributed to PC2, indicating that the position of horizontal kinetochore splitting determined the interspecific differences among Taraxacum chromosomes. The remaining traits dominated PC3. There were substantial differences in total chromosome length, total long arm length, and total short arm length among diploid, triploid, and tetraploid species, which explains the contribution of the indexes related to chromosome length to the PCs.
Cluster analysis of 18 Taraxacum species
The cluster analysis using karyotype data of the 18 species grouped the taxa based on their chromosome numbers and ploidy levels into three clusters, a diploid, a triploid, and a tetraploid clade. The diploid T. ohwianum was located between triploid and tetraploid species. Based on genetic distance, it was closer to the triploid species, and its rescaled distance threshold was between 10 and 15. Among the tetraploid species, T. coreanum formed a separate clade in the cluster topology, distant from other tetraploid species, confirming its independent species status. This may be related to the white color of T. coreanum, which differentiates this species from other Taraxacum species. The genetic distance among many triploid species was very small, supporting the interspecific merging of T. urbanum into T. antungense, T. asiaticum var. lonchophyllum into T. asiaticum, and the inclusion of T. formosanum and T. liaotungense into T. mongolicum in the Flora of China. In addition, the cluster analysis results supported the formation of a single group comprising T. sinicum, T. asiaticum, T. lamprolepis, T. antungense, T. heterolepis, and T. stenolobum, which are listed as valid species in the Flora of China, i.e., the division of Sect. 3 Sinensia V. Soest.