Fossil specimen of the lycophyte *Stigmaria* sp. from the Carboniferous of Illinois. *Stigmaria* is a rhizomorph, or root-like anchoring structure for ancient lycophyte trees. Note the helically arranged, circular rootlet scars. Specimen is from the Cornell University Paleobotanical Collection (CUPC), Ithaca, New York. Length of specimen is approximately 18.5 cm. Model by Emily Hauf.