Mycoglaena myricae (Nyl.) R. C. Harris

         No visible thallus but only perithecia (or better: perithecioid formations) level with the bark or barely prominent, circular to elliptical 0.2 to 0.4 mm in diameter, attached very superficially to the bark (their fall leaving only a simple imprint), blackish a little blue-greenish so fresh, typically edged with a circular silvery-white halo which gives them a cockade appearance. Asci with 8 spores, in an elongated club, 50-70 x 10-18 µm according to our measurements. Long ovoid spores with pointed ends, in the ascus first 1-septate and delimiting 2 slightly triangular cells, these cells then tighten towards their center giving the impression of a septum delimiting 2 cells of different sizes, which makes the spore appear as 3-septate, but rather it is an incomplete false septum and the spore could be considered only 1-septate, 16-20 x 4.5-7 µm according to the literature, 15 -18 x 5-7 according to our measurements. Absence of photobiont. Negative classic colored chemical reactions. Rare species typically coming on the old branches of Myrica gale and more rarely on the small branches of Betula, etc.. Species theoretically frequent on its host but which in practice is rare (or which goes unnoticed?), to be sought in marshes and peat bogs with Myrica gale which is a fairly common wetland species in Brittany but so far we have only found Mycoglaena myricae on Myrica gale in peat bogs not far from the sea.

N.B. Species probably not lichenized.