Axillary buds are initiated

Median longitudinal section of the shoot apex of St. John's-wort (Hypericum perforatum) showing the apical meristem between the pair of most recent leaf primordia. Also shown are a pair of primordial stipules beneath the youngest leaf primordia and above the primordial axillary buds in the axils of a third leaf pair (identify their stipules).

Note the procambium (the layer of elongated cells) in which primary vascular tissues are differentiating, as well as the ground meristem which may give rise to pith, and non-glandular trichomes.