Plants, in particular the model plant Arabidopsis thaliana, fulfill the above mentioned requirements. A classical attempt to describe the organization of the body of higher plants,
including Arabidopsis, relies on the concept of phytomers. A phytomer is a repetitive unit that consists of a leaf, a leaf attachment site including an axillary bud (nodium) and an associated piece of stem (internodium) (Gaudichaud, 1841;Gray, 1849). The variation of plant shoot morphology between most, if not all, higher plant species can be understood by
considering it as the phylogenetic and ontogenetic modification of this fundamental unit.