The architectural design of the plant's body of vegetation is very complex. Thin petioles carry heavy and flat laminas, stems support leaves, flowers and fruits. All plant organs are exposed to mechanical strains. Organs above ground follow the wind's drift. Their high elasticity lets them either return to their original position, or it makes them swing around an imaginative axis.
Trunks are stable enough to resist the wind's pulling.
They withstand pressure and are inflexible, although their projecting treetops provide the wind with a large target. The wind makes the upper plant organs and the trunk act like a lever, a large part of the force is hence exerted onto the roots. Other functions of the root are water and nutriment uptake and the anchoring of the plant in the soil. The strength of tissues protects also against enemies. The hard shell of many seeds prevents a chewing to pieces or puncturing by animals and avoids that parasites like fungi or bacteria force their way into them.