They seem really close at least, I’m not entirely sure how to tell them apart. In the smith key, P. longipes is grouped with 3 other species, two (P. fragilissima & P. elwhaensis) have been made synonyms of P. marcescibilis. The third (P. thomii) has larger spores and could be something else, maybe obs 97004 & 65825 are it?
Smith distinguishes them in the key with “Spores somewhat compressed laterally.” vs “Spores terete in cross section.” along with mostly small differences in spore size, but I understand now that P. marcescibilis has spores that are variable in size & shape… He also fails to include P. marcescibilis in his key, although he does consider it the type of section Fragilissimae. P. marcescibilis is reported for the states and I am pretty sure obs 129954 is it.
Here is a good reference on Psathyrella marcescibilis.
I also looked at genbank, but I didn’t see any P. longipes sequences…
Created: 2007-01-09 21:03:43 PST (-0800) by Nathan Wilson (nathan)
Last modified: 2010-03-03 10:31:47 PST (-0800) by Erlon (Herbert Baker)
Viewed: 817 times, last viewed: 2019-02-16 16:05:57 PST (-0800)