TABLE 3.

Summary of quadratic selection gradients (± SE) extracted from the literature for net selection (γ_C), non-pollinator-mediated selection (γ_HP) and pollinator-mediated selection (Δγ_Poll) on flower color estimated in natural plant populations and experimental populations.

Species	Trait	γC	γHP	γPoll	Reference
Natural populations
I. tenuituba, I. aggregata	Optical density	na	na	0.03 ± 0.10	Campbell et al. (1997)*
Mimulus luteus	Guide shape CVA1	na	na	6.338 ± 1.38	Medel et al. (2003)*
Mimulus luteus	Guide shape CVA2	na	na	2.580 ± 0.75
Claytonia virginica	Corolla color	−0.009	na	na	Frey (2004)
W. albomarginata	R440/R530	na	na	−0.091 ± 0.42	Campbell et al. (2012)*
W. albomarginata	PC1 (Color hexagon distance)	na	na	−0.563 ± 0.45
Iris atropurpurea, Year 1	Anthocyanin conc.	−0.958 ± 1.99	0.018 ± 2.35	−0.976	Lavi and Sapir (2015)
Iris atropurpurea, Year 2	Anthocyanin conc.	1.121 ± 0.59	1.329 ± 0.73	−0.208
Iris haynei, Year 1	Anthocyanin conc.	1.946 ± 2.43	2.266 ± 1.71	−0.320
Iris haynei, Year 2	Anthocyanin conc.	−0.060 ± 1.04	−0.554 ± 0.99	0.494
Anacamptis morio	Brightness	−0.270 ± 0.25	0.004 ± 0.06	−0.270	Sletvold et al. (2016)
Anacamptis morio	Lip patch size	0.320 ± 0.17	−0.022 ± 0.06	0.340
Anacamptis morio	Lip patch contrast	−0.022 ± 0.26	−0.021 ± 0.06	−0.001
Anacamptis morio	Lip spot area	0.074 ± 0.21	−0.002 ± 0.05	0.076
Iris lutescens, yellow	Anthocyanin conc.	n.s.	n.s.	n.s.	Souto-Vilarósa et al. (2018)
Iris lutescens, yellow	Flavonoid conc.	n.s.	n.s.	n.s.
Iris lutescens, purple	Anthocyanin conc.	n.s.	n.s.	n.s.
Iris lutescens, purple	Flavonoid conc.	n.s.	n.s.	n.s.
Iris lutescens, yellow	Anthocyanin conc.	n.s.	n.s.	n.s.
Iris lutescens, yellow	Flavonoid conc.	n.s.	na	n.s.
Iris lutescens, purple	Anthocyanin conc.	n.s.	n.s.	n.s.
Iris lutescens, purple	Flavonoid conc.	n.s.	n.s.	n.s.
Iris pumila, purple	Anthocyanin conc.	n.s.	n.s.	n.s.
Iris pumila, blue	Anthocyanin conc.	n.s.	n.s.	n.s.
Iris pumila, purple	Flavonoid conc.	n.s.	n.s.	n.s.
Iris pumila, blue	Flavonoid conc.	−0.900 ± 0.12	0.003 ± 0.03	−0.903
Medicago sativa	Brightness	n.s.	na	na	Brunet et al. (2021)
Medicago sativa	Saturation	n.s.	na	na
Medicago sativa	Hue	n.s.	na	na
Experimental populations
Penstemon digitalis	Nectar guide	0.004 ± 0.01	−0.006 ± 0.01	0.01	Parachnowitsch and Kessler (2010)
Centaurea cyanus	PC1 (Brightness)	0.020	na	na	Renoult et al. (2013)
Centaurea cyanus	PC2 (Blue-violet)	0.030	na	na
Centaurea cyanus	PC3 (UV)	0.003	na	na

Significant selection gradients at P < 0.05 are highlighted in bold. All selection gradients were estimated using multiple regression following the Lande and Arnold (1983) protocol. *Note that Campbell et al. (1997), Campbell et al. (2012), and Medel et al. (2003) estimated selection gradients based on pollinator visitations as fitness response rather than measurements of components of female fitness. I, Ipomopsis; W, Wahlenbergia; A, Anacamptis.