Abstract: Observations on the dichotomous leaf venation of Circaeaster agrestis found no intermediate forms of the fusion of vascular bundles between the two completely fused commissural veins of anastomoses and the two separate approximate veins, but found different degrees of the vestige of commissural veins . The fact indicates the impossibility of the formation of anastomoses from approximate veins. The occurrence of blind veins is related to the degeneration of teeth, the interruption of the commissural veins and the interruption of nonanastomosous veins at the branching point. Therefore, we considered the dichotomous leaf venation of this species as a reduced characteristic.

Key words: Circaeaster agrestis, Venation, Anastomosis, Blind vein, Morphology