Echinoplaca schizidiifera J. E. Hern. & Lücking
Mycobank MB 517766
Thallus foliicolous, up to 50 mm across and 20–30 µm thick, with cartilaginous, corticiform layer, uneven to coarsely verrucose due to incrustation with clusters of calcium oxalate crystals, with very scattered sterile setae, pale greenish grey to white; verrucae rather flat, irregular, 0.1–0.3 mm diam., white; setae 0.2–0.3 mm long, white or apically darkened. Thallus especially in inner parts dissolving into angular schizidia by disintegration; schizidia with the same anatomy as the thallus, 0.3–0.5(–1) mm diam., at first visible by irregular splits but eventually becoming involute and falling off, leaving behind small, rounded structured marking the attachment points. Apothecia not observed. Hyphophores not observed (but sterile setae might represent postmature hyphophores lacking diaphyphae). Secondary chemistry: no substances detected by TLC.
This new species is distinguished from all other species of Echinoplaca by the unusual vegetative reproduction via schizidia. Schizidia are otherwise unknown in the family Gomphillaceae but very similar schizidia have been described from species of Coenogonium in the related family Coenogoniaceae (Lücking, 2008). The schizidia of E. schizidiifera should not be confused with the disc-shaped propagules found in a species of the related genus Actinoplaca, A. gemmifera (Lücking) Lücking. In the latter, the discs produced on the thallus surface are homologous to hyphophores, whereas in the new species, the schizidia represent parts of the original vegetative thallus.
The epithet refers to the thallus dissolving into schizidia.
Echinoplaca schizidiifera was found inhabiting the leathery leaves of Clusia trees in upper montane cloud forest in Venezuela near the capital Caracas.
Type:—VENEZUELA: Distrito Federal: Parque Nacional El Ávila, zonas aledañas a Lagunazo; 10º33’N, 66º52’E; 2000 m; bosques nublados costeros de la Cordillera de la Costa, bosque siempreverde de media altura (20–25 m) con árboles emergentes que pueden alcanzar hasta 40 m; foliicolous; Aug 2008, Lücking 26084 (holotype VEN; isotype F).
Additional specimens examined (paratypes):—None.
Echinoplaca species thallo schizidiis disintegrantibus differt.