Branching Patterns and Mechanical Design in Palaeozoic Plants: a Theoretic Assessment

Abstract

Branching patterns of early land plants are given statistical descriptions and suggest that phyletic lines preserved geometric, elastic or static stress similarity in their growth habits. In general, most taxa fit within the theoretical limits of an elastic similarity model. Branching or dendroid structures are here defined as the result of three processes: (1) bifurcation, (2) growth and (3) pruning; an overview of fossil specimens permits an ‘instantaneous’ description of dynamic processes and indicates a general maintenance of branching ratios within genera. It is proposed that tree-like Palaeozoic plants limited growth (overall height) by 1/4 the critical buckling height of a uniform cylinder having the same base diameter of the plant loaded under a comparable weight. A theoretic assessment of branching modes is presented within the context of botanical evolution.