The choice of apical region to initiate in vitro cultures of C. officinalis replaces the addition of exogenous auxins and
is an alternative to obtaining the highest quantity of rooted plants. The explant source is a way to take advantage of the
plant potential to synthesize auxins in plant apices (PEER;MURPHY, 2007). Additionally, these results agree with indications that endogenous auxins are mainly biosynthesized at the young developing leaves, shoot apical meristems, and plant stems (BOUTTÉ; IKEDA; GREBE, 2007).