Aquatic Lythraceae remains were first recognized in the Princeton chert by Cevallos-Ferriz and Stockey in 1988 with the description of fruits and seeds of Decodon allenbyensis . Specimens of the vegetative remains thought to belong to D. allenbyensis were studied using the cellulose acetate peel technique in an attempt to reconstruct the whole plant. Roots and stems show diffuse porous wood with vessels that are solitary or in radial multiples of two to five with numerous tyloses.
Heterogenous rays vary from one to at least five cells wide.
Secondary phloem with clusters of thick-walled fibers is preserved in some axes. Most of the roots and some stems show distinctive concentric layers of thin walled lacunate phellem, characteristic of submerged aquatics. Leaves, roots, stems, seeds and inflorescence axes of D. verticillatus have been studied using paraffin techniques and scanning electron microscopy and were closely compared to these remains in the chert. Anatomy of D. allenbyensis suggests that these plants were growing under submerged conditions with fluctuating water levels at the edge of a shallow water system.