Bacidina assulata in the New Forest

Nice to have the forum back and to have all the old posts imported, thanks.

Just to see if it works I will put up some pictures of a recent find from my searching twigs in the New Forest to map Lecanora pseudargentata across the Forest. There are clearly a lot of Bacidina species on the more nutrient enriched twigs, but these are rarely fertile. I have had some Bacidina adastra but nothing much else fertile. So when I spotted some tiny apothecia on a Beech twig in a 19th century Oak plantation I collected them.

Bacidina apothecia

The apothecia were on a bright green somewhat warty thallus, there were some possibly associated clumps of pale green soredia, suggesting Bacidina caligans, but if that is what they were, the apothecia and pycnidia did not match. The apothecia were buff-brownish, and pale to colourless inside with brownish tones in the outer exciple and epithecium. The spores were 30 – 38 x 1.5 µm and acicular. Along with the thallus not being composed of microsquamules, the spores were too short to be Bacidina neosquamulosa. It still could have been Bacidina caligans, but finding some pycnidia ruled this out, the conidia were too long (40 – 55 x 1 µm) and slightly bent at one end or hooked at one end: this seemed to be Bacidina assulata (Bacidina mendax) which was has so far only had one official record from Britain (see collected at Kew Gardens), but I did help someone identify it at a BLS winter workshop, but forgot to get the details of that second specimen. It should be widespread in Britain from its European distribution (also see).

Some pictures:

Bacidina assulata apothecia cross section in K

Bacidina assulata spores in K

Bacidina assulata pycnidia

Bacidina assulata conidia

Bacidina assulata conidia

Anyway worth looking out for fertile Bacidina species on twigs, there should be more of this about.

Neil