Figure 2.

Schematic of the greenhouse crossing design to generate seeds for our common gardens. Three blocks are diagrammed here, but crosses were performed in 22 blocks and seeds from 15 blocks were transplanted into the field. (A) Within‐population crosses: for each seed family from each of 15 populations (three are shown), plants were crossed in a “daisy chain” design, in which each plant was hand‐pollinated using pollen from another individual of the same population from the subsequent block. (B) Between‐population crosses: we used pollen from each of 13 donor populations (two are shown) to pollinate flowers on plants from each of the two focal populations (one is shown). Each focal plant served as a dam for multiple between‐population crosses, that is, each focal seed family had one flower pollinated by a plant from each of 13 donor populations and from the other focal population.