Polycyclus Höhn., Sber. Akad. Wiss. Wien, Math. -naturw. Kl., Abt. 1 118: 1542 (1909).
Index Fungorum number: IF 4312; Facesoffungi number: FoF 02329, 2 morphological species (Species Fungorum 2022), no molecular data available.
Parasitic on host. Sexual morph: Without free mycelium. Stromata black, roundish or elliptic, epiphyllous, single or grouped, having 3 to 5 concentric rings in relation to the hypostroma, pressing against the epidermis, producing an ash-colored protuberance on the leaf surface. Superior wall of the stromata dark-brown, opaque, clearing to the margins, forming rectangular cells of textura angularis, the free end of the margins undulant and entire. Inferior walls are dark-brown, having several layers from these layers the basal one shows grouped parallel cells, while the top layer, dark less than the other is composed of roundish or ellipsoid cells, loosely disposed, sometimes the layer of parallel cells is disposed over a pseudo tissue of polyhedric cells irregularly disposed. The locules are generally entire with a longitudinal rima as long as the wideness of the locule. Hypostroma central formed by a pseudoparenchymatic body, ellipsoid, brown, sub-epidermal from which brown hyphae developed freely or in ropes going to the mesophyllum. Asci cylindric-clavate, sessile or short stipitate, 8-spored, aparaphysate. Ascospores lengthened-ellipsoid, uniseptate, constricted, the cells unequal, at first hyaline, turning brown, irregularly distichous. Asexual morph: Unknown (adapted from Batista and Vital 1960).
Type species: Polycyclus andinus (Pat.) Theiss. & Syd.
Notes: Polycyclus was introduced by Höhnel (1909) without designation of a type species. Theissen and Sydow (1915) chose P. andinus as the type species. Polycyclus is characterised by black, roundish or elliptic, epiphyllous stromata, cylindric-clavate, sessile or short stipitate, 8-spored asci and ellipsoid, uniseptate ascospores. Inácio and Cannon (2008) did a morphological comparison between P. andinus and P. marginalis and reported that the two species might not be conspecific. Polycyclus is a distinct genus in Parmulariaceae but molecular data is lacking. Fresh collections with DNA sequence data are needed to confirm the taxonomic placement of the genus.