Here is a cool shot of a pine in Dunwich Forest, where the main leader has been lost and the suppression of side shoots was no longer apparent. Therefore, a mad frenzy for a new leader began, and in the case of this tree the fight for dominance still remains strong. Reiterations and growth hormones galore! We also have the concept of the minimum lever arm coming into play, by where the adventitious growth has led to the stems swiftly adopting an upright stance in a bid to reduce the loading upon the structure. A prime place for a bird nest, I would say. Excurrent-no-more. Ex-excurrent?