This stocky blackish dragonfly with yellow ringed abdomen is about 2.2 inches long. The thorax has some yellow stripes, near shoulders. There are small yellow spots along the abdomen. A male is easily identified by its leaf-like expansions on its club's segments edged with yellow. The female's abdomen is very stout and clubless.
Common throughout northeastern United States and southeastern Canada, this species is usually found in forest streams with intermittent rapids, including trout streams with sandy/mucky bottoms. Females are reclusive and rarely seen. In Wisconsin, it is widespread, but found infrequently, throughout northern two-thirds of the state.
Late June to late September in Wisconsin.