This is one of the earliest flying Catocala as an adult and the larvae likewise mature early in spring. Among the Rosaceae-feeding species, clintonii has among the densest as well as most strongly branched lateral filaments, and the typical vertical horn on A5 is reduced to a low bump (often somewhat conical viewed laterally). Coupled with its comparatively more rounded head capsule, relatively concolorous head capsule face with few dark patches and a distinctly lighter supra-mandibular area, these characters make identification rather straightforward. Wild foodplant records include hawthorns (Crataegus) and plums (Prunus).