Natural hybridization between two butterfly bushes in Tibet: dominance of F1 hybrids promotes strong reproductive isolation

Table 1 Morphological traits used to distinguish between B. alternifolia, B. crispa and B. × wardii

Characters	B. alternifolia	B. × wardii	B. crispa	F	Welch	P value
L (mm)	16.00 ± 3.15^a	27.31 ± 10.02^b	64.65 ± 25.47^c		62.971	< 0.001
W (mm)	3.62 ± 0.66^a	14.00 ± 3.26^b	36.61 ± 11.72^c		235.112	< 0.001
L/W	4.52 ± 0.99^a	1.94 ± 0.47^b	1.76 ± 0.31^b		97.410	< 0.001
TL (mm)	7.10 ± 0.80^a	9.77 ± 1.04^b	10.25 ± 1.51^b		79.584	0.017
TW (mm)	0.93 ± 0.17^a	1.09 ± 0.15^b	1.20 ± 0.18^c	17.584		0.641
CLL (mm)	1.43 ± 0.27^a	2.29 ± 0.37^b	2.17 ± 0.40^b	49.695		0.073
CLW (mm)	1.60 ± 0.20^a	2.41 ± 0.35^b	2.45 ± 0.46^b		80.282	0.004
AH (mm)	5.22 ± 0.76^a	5.97 ± 0.93^b	6.66 ± 0.96^c	18.266		0.539
SL (mm)	2.89 ± 0.47^a	4.14 ± 0.91^b	4.41 ± 1.05^b		46.621	0.001
HE (mm)	1.08 ± 0.67	0.75 ± 0.72	0.95 ± 0.87	1.261		0.588

1 L leaf length, W leaf width, L/W ratio of leaf length to leaf width, TL corolla tube length, TW corolla tube width, CLL corolla lobe length, CLW corolla lobe width, AH anther height, SL style length, HE herkogamy

ISSN: 1471-2229