40-centimetre scaly polypore found on Teisko sauna may be bitter, expert warns

Tomi Kumpulainen, curator at the Tampere Museum of Natural History and Aamulehti’s nature columnist, warns against eating a large, unidentified mushroom that appears annually on the lakeside sauna at Lauttajärvi in Teisko. Don't eat it. From the photograph he identified the fungus as a scaly polypore, but said a precise species determination requires examining the cap underside and stem.

The reader who sent the photo estimated the fungus at about 40 centimetres across and noted a pored underside. Kumpulainen says two similar species can be confused: the spruce scaly polypore tends to be more funnel-shaped, paler on top and has large scales concentrated in the centre, while the pine scaly polypore is darker, more convex and bears large scales across the cap. Only the pine form is edible; the spruce form is very bitter and inedible, so accurate identification matters. This echoes the museum expert's earlier note that exact species often cannot be determined from photographs alone.

He asks readers to photograph both the top and underside of mushrooms and to include location, time and estimated size when sending images to [email protected]. His column covers observations from Pirkanmaa but he will reply to other queries when possible.