Behaviour of eversporting gymnosperm chimeras indicates a single apical cell is present in the shoot apical meristem. Korn studies one Mentha (Lamiaceae), one Euonymus (Celastraceae) and four Spiraea (Rosaceae) cultivars to determine the fate of the yellow (mutant)–green (wild type) chimeras in order to see if eudicot chimeras have the same behaviour. He finds that unstable chimeras became stable yellow about 80 % or more of the time and 20 % or less became stable green. The statistically significant preponderance of chimeric fates becoming all yellow suggests that a single apical cell resides in the yellow tunica. As with gymnosperms, descendent cells of the yellow replacement corpus cell eventually take over the corpus. The results provide the first chimeric set of data to support the hypothesis of a one-celled meristem in eudicots rather than the traditional view of a muticellular meristem.