Species hybridus (Williamson, 1902) [Gomphus]
Cocoa Clubtail is uncommon in the eastern portion of the region. Its face and thorax are greenish. The females have a short erect spine at the end of each postocellar ridge. A dark middorsal thoracic stripe widens toward the collar only slightly and is divided by a pale carina. The antehumeral stripe is wide, often contacting the humeral stripe in one or more places, but becoming free at its upper end. The midlateral stripe is present but often interrupted above the spiracle, while the third lateral stripe is present and well-developed. The legs are black with only a pale yellow line on the outer surface of the tibiae. The wings are clear with a dark pterostigma. The abdomen is dark brown or black with an interrupted middorsal stripe. The basal segments are yellowish-green laterally. Segments 7-9 are widened laterally and darker than the preceding segments, often lacking any yellow dorsally on segment 9. Segment 10 either has a round yellow spot dorsally or is entirely black. The male cerci are divergent when viewed dorsally.
Total length: 48-53 mm; abdomen: 34-38 mm; hindwing: 27-32 mm.
Segment 9 of Plains Clubtail (G. externus ) has a dorsal yellow stripe and lateral yellow spots on segments 8-9. Ozark Clubtail (G. ozarkensis ) is larger and darker. It also has a larger pale yellow spot laterally on segment 8. Cobra Clubtail (G. vastus ) is larger and has the dark thoracic stripes separated.
Large turbid rivers with moderate current and sandy bottoms.
Males seem to prefer perching on the bank in semi-shaded areas. They are not active patrollers. Cobra Clubtail has been reported from Louisiana, but these records are most likely Cocoa Clubtail.