Hi all,

I collected this saxicolous crust from a rock in view of the ocean in northern California, as part of a CALS bioblitz.  I think it might be Porpidia (crustulata?) but was hoping to get input from more experienced folks.   My ID notes are below:

A crustose lichen where the thallus is partly eroded away and elsewhere quite thin, patchy and cream-colored, with a green algal photobiont. The lecideine apothechia are 0.5-1.5 mm in diameter and cross-sections show a pale hymenium, dark blue-green epihymenium and a dark brown hypothecium. Asci are narrow and contain eight simple, hyaline spores measuring about 13 x 8-9 microns. Polarized light shows some POL-positive streaks in the hymenium and small crystals in the epihymenium. The exciple appears quite narrow and is hard to see well, but appears to be brown. KI staining is hard for me to interpret.

Thanks!

Ken S.

That pigmentation pattern is typical for a number of Lecidella species. The iodine reaction of the tholus shows very well in one photo, also typical of Lecidella. I think that L. asema is likely.

Sometime the paraphyses are freer than others, but you can always find a few individual paraphyses splaying away from others on the edges after a little pressure. This is unlike a true Lecidea where the hymenium tends to fragment in blocks.

Hi all,

I thought it would be of interest to post a quick follow up on this specimen - I was able to get an ITS DNA barcode and it matches to Lecidella as best I can tell, but does not seem to be a perfect match to L. asema or anything else in Genbank by a BLAST search. 

https://www.ncbi.nlm.nih.gov/nuccore/PX532388.1?report=GenBank