The shoot apical meristem (SAM) is the key organizing element of the plant body. Surprisingly, there are almost no across-species comparative data showing links between the SAM and whole-plant traits such as leaf size, stem diameter or seed mass.
Schnablová et al. show that such relationships do exist, and moreover, that as a result of recent convergent evolution species differ in their SAM cell number, which is correlated with a number of plant traits. This study suggests that SAM indeed provides a strong link informing traits of plant organs, and is a key component of plant’s evolutionary response to the environment.