Missouri has several species of orb-weaving spiders in genus Neoscona, all called spotted orbweavers, and some are quite difficult to distinguish, even by specialists. Often, you must observe small details of their anatomy in order to determine the species.
Neoscona species have a slightly triangular-ovate abdomen with a pattern resembling an upside-down spruce tree. On each side of this midline may be black, brown, and greenish-brown markings. The legs usually are gray with brown rings. The carapace may be gray with brown markings.
Similar species: Araneus species may be similarly marked and colored, though some are quite showy and less hairy. To separate these two genera of "barn spiders," one must examine the fovea (which is a groove, pit, furrow, or other depression in the center of the carapace, the shieldlike covering of the cephalothorax, the "head" part of the spider's body). In genus Neoscona, the fovea is a lengthwise groove that runs parallel to the length of the spider's body. In genus Araneus, the fovea comprises angular or transverse grooves that run side to side across the spider's body; in some Araneus species, the fovea is little more than a dimple.