Table 1.
Study pairs and floral features
| Region | Family | Pair | Taxa | Code | Range | Sites | Symmetry | Colour | Nectar | Mating | Ovules |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Andalusia | Cistaceae | 1 | Fumana baetica | Fub | E | 2 | Actino | Yellow | No | SC | 9 |
| Andalusia | Cistaceae | 1 | Helianthemum appeninum appeninum | Hcr | NE | 2 | Actino | Yellow | No | SI | 16·7 ± 1·3 |
| Andalusia | Cistaceae | 2 | F. paradoxa | Fup | E | 1 | Actino | Yellow | No | SC | 6 |
| Andalusia | Cistaceae | 2 | H. cinereum | Hci | NE | 1 | Actino | Yellow | No | SC | 6 |
| Andalusia | Caryophyllaceae | 3 | Silene psammitis lasiostyla | Spl | E | 2 | Actino | Pink | Yes | SC | 33·3 ± 0·9 |
| Andalusia | Caryophyllaceae | 3 | S. colorata | Sco | NE | 2 | Actino | Pink | Yes | SC | 53·8 ± 2·2 |
| Andalusia | Lamiaceae | 4 | Thymus orospedanus | Tho | E | 2 | Zygo | Pink | Yes | SC | 4 |
| Andalusia | Lamiaceae | 4 | Sideritis incana | Sii | E | 1 | Zygo | Yellow | Yes | SC | 4 |
| Andalusia | Lamiaceae | 4* | Teucrium polium | Tpo | NE | 2 | Zygo | Beige | Yes | SC | 4 |
| California | Liliaceae | 5 | Triteleia peduncularis | Trp | E | 5 | Actino | White | Yes | SI | 27·7 ± 0·8 |
| California | Liliaceae | 5 | Zigadenus venenosus | Ziv | NE | 5 | Actino | Beige | Yes | SI | 20·4 ± 0·4 |
| California | Ranunculaceae | 6 | Delphinium uliginosum | Deu | E | 5 | Zygo | Purple | Yes | SC | 31·4 ± 1·5 |
| California | Scrophulariaceae | 6 | Antirrhinum cornutum | Anc | NE | 5 | Zygo | Purple | Yes | SI | 62·3 ± 3·6 |
| California | Phyrmaceae | 7 | Mimulus nudatus | Min | E | 5 | Zygo | Yellow | No | SC | 179·2 ± 14·9 |
| California | Phyrmaceae | 7 | M. guttatus | Mig | NE | 5 | Zygo | Yellow | No | SC | 240·9 ± 28·3 |
| Yucatan | Malvaceae | 8 | Cienfuegosia yucatanensis | Cie | E | 2 | Actino | Yellow | Yes | SC | 16·4 ± 0·4 |
| Yucatan | Malvaceae | 8 | Sida acuta | Sid | NE | 2 | Actino | Yellow | Yes | SC | 5·9 ± 0·1 |
| Yucatan | Lythraceae | 9† | Cuphea gaumeri | Cup | E | 1 | Zygo | Purple | Yes | SC | 25·6 ± 1·6 |
| Yucatan | Scrophulariaceae | 9 | Angelonia angustifolia | Ang | NE | 1 | Zygo | Purple | Yes | SC | 53·5 ± 0·7 |
| Yucatan | Lythraceae | 10† | C. gaumeri | Cup | E | 1 | Zygo | Purple | Yes | SC | 25·8 ± 1·0 |
| Yucatan | Verbenaceae | 10 | Tamonea curassavica | Tam | NE | 1 | Zygo | Purple | Yes | SC | 4 |
Taxa were categorized according to distribution range, distinguishing between endemics (E) and non-endemics (NE); floral symmetry, distinguishing between actinomorphic (Actino) and zygomorphic (Zygo); presence of nectar as a reward; and mating system, distinguishing between self-incompatible (SI) and self-compatible (SC) plants. The number of ovules was constant in some taxa; for those that were variable, we show an average (± s.e.) obtained from a small independent sample (8 ≤ n ≤ 20). The number of sites where samples were collected is also indicated.
*Teucrium polium was compared against two endemic species, although one of them was only collected in a study site in which the three coexist.
†Cuphea gaumeri only coexists with each paired species within a single study population; thus, population data were not merged.