Collection location: Mountain View, Santa Clara Co., California, USA [Click for map]
Found these in a lawn near some pine trees. What are they?
Actually when you search for “Tricholoma fracticum” the Index Fungorum says:
Tricholoma fracticum sensu auct. mult., (= Tricholoma batschii), [RSD]; Tricholomataceae
Tricholoma fracticum (Britzelm.) Kreisel (1984); Tricholomataceae
This does not mean that T. batschii a preferred synonym for T. fracticum. What it means is both species are valid and distinct. It also indicates that T. fracticum was applied to what was later described as the separate species T. batschii. If someone gets hold of Persoonia 17(2): 315 (1999), they should be able to clarify what separates these two species. In the meantime, I recommend continuing to use T. fracticum at least for California material, since that name is used in “Agaricales of California”.
Thanks, that looks like a match! Looks like the newest synonym for this species is Tricholoma batschii according to Index Fungorum.
With the small white smooth spores, it looks like a Tricholoma. Near the pine trees, it is probably T. fracticum, which can get all brown in age. They also dev. brown stains on the gills in age. So, these are probably old T. fracticum.