The males of most of the "hanging" clubtails (genus Stylurus) have long, slender abdomens. When perched on leaves, the bodies are pulled down by their weight, creating the appearance of "hanging" clubtails. The body length of the riverine clubtail varies from 1.8 to 1.9 inches. The pale markings on front of the thorax generally compose a 3-pointed star. On the sides of the thorax, a pair of wide stripes are angled slightly downward with a very narrow green shoulder stripe. The face is yellow-green with black lines and green eyes. The hind thighs are yellow. The male club has large yellow lateral spots with black lateral edges, near the end of the abdomen. The female is yellower than the male. The similar elusive clubtail differs in not having a frontal star and some other characteristics.
Found throughout northeastern United States and some states in the southeast, the riverine clubtail likes fast-moving medium to large rivers with sand, gravel, or mud bottoms. It is widespread throughout Wisconsin, although not in abundant numbers.
In Wisconsin, adults have been documented from early June to early August.