[1] The species is known from massive tree trunks that weather out of the Chinle Formation in desert badlands of northern Arizona and adjacent New Mexico, most notably in the 378.51 square kilometres (93,530 acres) Petrified Forest National Park.

The purple hue comes from extremely fine spherules of hematite distributed throughout the quartz matrix, and not from manganese, as has sometimes been suggested.

Modern conifers, on the other hand, typically bear a circular cluster of relatively small, narrow roots.

[1] In the Triassic period (around 250 to 200 million years ago), Arizona was a flat tropical expanse in the southwest corner of the supercontinent Pangaea.

Fossils frequently show boreholes of insect larvae, possibly beetles similar to members of the modern family Ptinidae.