Gyalecta jenensis var. macrospora forma

    Differs from Gyalecta jenensis var. macrospora by its thallus, mostly inconspicuous or limited to minute dark-brown fragments only visible under magnifying lens. We differentiate two sub-forma:

_ One form with apothecia lying on a blackish biofilm of cyanobacteria (Nostoc) in addition to Trentepohlia, growing on micaschist rocks in the xeric zone with seawater splashes and to seaspray in exposed rocky cliffs.

_ An another form growing on armorican sandstone rocks in maritime cliffs, exposed to seaspray, without visible thallus but with abundant colonies of free Trentepohlia.

For the two : Ascii 8-spored, elongated, 115-170 x 15-20 µm according to our measurements. Ascospores very ellipsoid, muriform, colourless to faint yellow when mature, 25-37 x 11-15 µm according to our measurements. N.B. It is not known yet whether Nostoc participates to the biology of this form, or whether its presence is limited in time in order to enhance the survival probability of the Gyalecta host in this particularly hostile habitat, or even if the Nostoc is "free" and there just by chance.

N.B. Another distinctive feature: this form is always the companion of Anaptychia runcinata, with which it seems to share the same habitat.