Intercalary growth plays a roll in elongation of the stems and the cones and is documented by time-lapse cinematography, elucidated by longitudinal sections and in computer simulations. In the evergreen rough horsetail lateral branching occurs following abandonment of apical dominance; in other horsetail species it is the rule. The structural principle of the horsetail has correspondences in architecture, e. g. Indian minarets (Qutub Minar).