This large damselfly earns its common name from its dark metallic, cryptic colouration, which perfectly camouflages it against the mottled, lichen-covered boulders upon which it habitually sits.

Its body is primarily black, but features brown markings along its long, slender abdomen, it is particularly at the joints between segments, and is bluish, slate-grey colouring at the tip.

Despite its historical declines, however, the current population of this species appears to be stable, both in range and size, and habitat destruction, mostly for plantation forestry, has largely subsided.

Alien invasive trees, which shade out the habitat, are considered one of the most pervasive and significant threats facing specialized, endemic South African dragonflies and damselflies.

The programme has been a fantastic success story, with other dragonflies and damselflies like Pseudagrion newtoni that were presumed to be extinct being rediscovered along river stretches where invasive alien trees were removed and the natural vegetation reestablished.