monophylly

Updated: May 4, 2025

Of course the comparison only relates to a single character, and the movements of the leaflets are not affected by it. But the monophylly, or rather the size of the terminal blade and the reduction of the lateral ones, may be held to be sufficiently illustrated by the bastard-acacia. It is worth while to state, that analogous varieties have also arisen in other genera.

Hugo de Vries - Species and Varieties, Their Origin by Mutation

These monophyllous varieties are interesting also on account of their continuous but often incomplete reversion to the normal type. Pinnate and palmate leaves are no doubt derivative types. They must have originated from the ordinary simple leaf. The monophylly may therefore be considered as a reversion to a more primitive state and the monophyllous varieties may be called atavistic.

Hugo de Vries - Species and Varieties, Their Origin by Mutation