Ascomataca 100 µm diam., with erect thick-walled simple tapered acute red-brown setae 40-66 µm long and 5-6 µm at the base, on abaxial surface of leaf, on a subiculum composed of yellow-brown hyphae with yellowish crystalline deposits in the interstices. Asci 36-42 x 10-20 µm. Ascospores 16-20 x 4-5 µm, 3- to 4-septate, slightly constricted at the septa.
The affinities of this species lie with Chaetothyrium and Ceramothyrium (Chaetosphaeriales) rather than the Tubeufiaceae. A. hederae was not treated by Réblová & Barr (2000).