If they are freshly picked and havnt dropped spores yet you can cut the cap off, make sure the veil isnt in the way, lay on a piece of tinfoil and put in a safe place for a day or two, you should come back to a nice spore print.
If the spores already dropped, you can still swab the cap and drop into a liquid culture you might get something.
You can also take inner tissue samples with a clean scapel, drop in a liquid culture or petri dish and you can get some mycelium started that way.
If you know how to make substate jar for mushroom growing (wild bird seed/mason jars have always worked for me) you could drop these same spores or tissue samples in there and maybe getting something going.
One more trick you could do if you have a fresh mushroom (you might be able to pull it off with a dried one but the probabilty of contamination would be very very high) take your hopefully clean shroom, cut the cap off. throw the stem in a CLEAN blender with some distilled water. Suck up the blue mush water into a clean syringe and then BAM you have a syringe that can knock up substrate jars.
Seek not abroad, turn back into thyself, for in the inner man dwells the truth.