Vascular bundles in plants transport sugars, minerals and water, which is a limiting factor for yield realization. Huang et al. (pp. 81–90) report high resolution genetic analyses of the number of vascular bundles in maize stem using a large maize‐teosinte population. Results showed that the vascular bundle number is controlled by a large number of small‐effect QTLs that might not be under directional selection during domestication.