Gamundia striatula (Kühner) Raithelhuber

 Lichenicolous Basidiomycota growing on Peltigera sp.

    Pileus up to 1-3 cm diam., convex at first then plane with a central depression, hygrophanous and translucently striate, upper surface smooth, slightly gelatinous when moist, pale brown, pale brown-yellowish, pale grey-ochre, slightly fuliginous towards the center. Lamellae  slightly curved, adnate-emarginate to decurrent, white, sometimes with greyish or pinkish tinge. Stipe cylindrical, 2-4 cm long, whitish. Flesh whitish, weak odor of flour. Basidia: 2-4-spored. Ascospores broadly ellipsoid, not amyloid, very minutely verrucose (often difficult to observe), 6-8 x 3,5-5 µm. Cheilocystidia numerous, cylindrical to fusiform, sometimes clavated, 25-40 x 5-14 µm, pleurocystidia less numerous, identical or cylindrical-fusiform. Pileipellis with congophobic hyphae on upper surface and incrusted hyphae below, hyphae neither amyloïd nor dextrinoid. Clamp-connections distributed all over. This species grows during late fall and winter on dry sandy soils with abundant mosses and lichens. In our prospection area (and elsewhere), this species is found on or close to Peltigera sp., notably  Peltigera hymenina  (sometimes at the basis of Cladonia sp. according to literature). Whether or not this species is lichenicolous, parasitic of lichens or saprophytic is still a matter of discussion since its phylogenetic status has dramatically changed (and still change) in recent times. This explains the abnormal list of synonyms (or supposed to be). Due to this general confusion, it is not clear whether or not it is only one species highly variable, or several taxa. This complexifies the understanding of its interactions with Peltigera sp., nevertheless according to the latest work, it seems that this species is simply lichenicolous. We consider here this species stricto sensu in order to simplify future observations. N.B. Not to be confused with Arrhenia peltigerina (Peck) Redhead that is very similar and also lichenicolous of Peltigera sp., but devoid of cystidia.*