During the geologic epoch in which the Stockton formation was laid down and the igneous diabase intrusions that would eventually be quarried here were implaced, plant life, although varied and lush, was by modern standards ‘primitive’. Flowering plants, including all our deciduous trees, herbs, grasses, and sedges, had not yet evolved. Ferns, clubmosses, horsetails, pines, and their allies were the only vascular plants growing on the Earth at that time, although many of the latter named groups often achieved impressive heights, witness the many fossils found in the coal beds laid down in Carboniferous times.
Although none of the species growing three hundred million years ago are still present today, at least eighteen of their relatives and descendants can still be found growing at Triassic Park. These include a clubmoss, a horsetail, eleven ferns, and five conifers. The pines, hemlocks, and red cedars are easily the most visible members of this group on the property, especially in winter, but during the growing season many of the other species, especially the ferns, can be easily observed during a stroll through the woods.