Good evening to all,

At the dried out edge of a swamp, on plant debris, I found dozens of ascomata of Lachnum (diameter < 2 mm). On twigs (alder, willow, birch, oak) with diameters < 10 mm and also on an alder catkin.
The hymenium is white and turns brown after damaging or ageing. Very striking: some ascomata have a bright blue/purple hymenium (in the field I remember more blue!).

Miccroscopy:
a) Hairs without oxalate crystals, almost no refractive vacuoles and apex capitate, 44-70 x 3-5 µm
b) Paraphyses only very faint refractive vacuoles; 53-57 x 3.7-5.3 µm; protruding 14-17 µm
c) Asci with croziers, IKI +; 46-59 x 3.7-5 µm
d) Spores: (6.2) 6.4 - 8.1 (9.9) × (1.1) 1.6 - 2.1 (2.3) µm; Q = 3.2 - 4.6; Me = 7.3 × 1.9 µm ; Qe = 3.9

On microscopic examination of the blue/purple-coloured ascomata, I had the impression that they were overripe. Spores were floating massively in a pulp of conidia in which a slight shade of blue was visible. In another specimen, very fine hyphae turned blue when the hymenium was cut with a scalpel.
Is Lachnum subvirgineum a correct determination? What can be the cause of the blue/purple discolouration, does anyone have experience with this phenomenon?


Thank you very much in advance,

François Bartholomeeusen