Figure 1.

Temperature-adjusted species means (±1SE) for exilis (a selfer, black bars) and unguiculata (an outcrosser, grey bars) for pollen performance traits following cross-pollinations and self-pollinations conducted in field populations during spring 2008. (A) and (B): pollen tube growth rate (PTGR). (C) and (D): proportion of the entire style length traversed by pollen tubes that entered the style within 2.5 hours of pollination. An asterisk (*) indicates cases where a given pollen performance trait differs between sister species (p < 0.05).