Moe and more, people are calling me for help identifying mushrooms. Sometimes it is easy to do, and at other times it is difficult. I thought posting a blog entry on the latest trial would help others know what kind of characteristics to examine in order to make an identification effort fruitful.
Mike put in a wood chip patch in February and inoculated it with Wine-Cap Stropharia spawn, Stropharia rugosoannulata. On November 4, he found a flush of mushrooms, but they had a beige cap rather than the wine colored cap he expected. He felt it wise to get a positive identification prior to eating them (good thinking). We met and he brought this mushroom.
Although the cap was off color, it had many of he features of the wine-caps. Michel Kuo mentions, on his web site, the occurrence of a light colored variety http://www.mushroomexpert.com/stropharia_rugosoannulata.html. Considering this, I contacted Park Seed Co. where Mike had gotten the spawn to see if they dealt with this variety, but they no longer carried Stropharia. In addition, I have read nowhere that S. rugosoannulata has appressed scales on the cap, which the specimen clearly has under stereoscopic microscopy. I was not able to get a good enough slide to view cellular structure. The cap has an orangish reaction to KOH, consistent with Kuo, but the specimen did not have a creosote-like odor. It was dried up however. The cap had the “pop” of a normally viscid cap when the wet finger test was applied. (Wet your finger and touch the cap while holding it close to your ear; you can hear a pop when you quickly pull your finger back off of the cap)
The sample mushroom was 6-inches in diameter and about 5-inches tall. From this picture one can see a spore deposit on a strong annulus (ring). I agree that the spore deposit is purplish-brown and the spore images under a microscope are consistent with Kuo’s. In addition, the gills are adnexed, notched.
The flesh is white; the smell was weak. There are also radial lines on the stipe above the ring. Below the ring the stipe has vertical fissures in the surface tissue. The base of the stipe is enlarged. Also, notice the ring is split in the next picture which is consistent with David Aurora’s (Mushrooms Demystified) description, as is the tan cap. .
So where does this leave us? Would you accept this as an atypical S. rugosoannulata and eat it? I am concerned about the appressed scales on the cap. Other than that, it sure looks like a Stropharia. Read Kuo’s description and see what you think. I’ll bring you my answer later. Feel free to comment. . . . .