Fossilized stigmaria

Nice specimen! Interesting colors and details. Great addition to any fossil collection! Full description: Stigmaria is a form genera name for the roots of Carboniferous lycopod (scale) trees. Form genera are genera defined for a part of an organism or plant, rather than the whole organism or plant. Because plants, especially large plants such as trees, are commonly fossilized as parts (leaves, bark, cones, trunks, roots, etc.), which are found separate from each other, the different parts are given distinct names. Stigmaria are the roots of extinct lycopod trees, including the lycopods Lepidodendron and Sigillaria. Stigmaria fossils are generally elongate and tubular. They range from almost circular to flat in cross section. Their outer surface is smooth to crenulated or rope-like, and commonly ornamented with many circular or oval depressions a centimeter or less in diameter, arranged in spiraling patterns. The rims, and sometimes center of the depressions, may be slightly raised. These depressions are where rootlets attached to the main roots. In cross section, some specimens will preserve an axial core, which is the pith cast of the original root. Some specimens are rounded or convex on one side, and depressed or concave on the other, with a groove or depression oriented along the long axis of the fossil root. In shales and coaly shales, the elongate tubular parts of Stigmaria may be surrounded by thin, hair-like rootlets. - University of Kentucky