Forum Flora Germanica

These are 2 separate specimens, couple of m apart, cap like 15 cm,one should be Caloboletus calopus, the other ?
Any chance red stem color disappeared somewhere. Gills had no bruising until I turned it around.
Also I don't think stem was yellow at any point.

I can’t say much about the photos (cross-sections would always be helpful to check for discolouration), but apart from Caloboletus calopus (and Caloboletus radicans, which can also develop a little red at the very base as it ages), there is also – particularly in the south (as far as I am aware) – Caloboletus polygonius. There should be no reticulation on the stem (or only a little at the very top), and the reddish colour should appear in fibres or a granular form.
However, some photos (provided they’re correctly identified…) also show very little red and no distinct yellow. As they age, mushrooms generally become increasingly ‘unattractive’, but the red usually persists, whilst the yellow sometimes turns ochre.
However, as I have read, the presence or absence of a stem net is not a definitive distinguishing feature between *calopus* and *polygonius*; one should test the stem flesh with Melzer’s reagent (amyloid reaction): *calopus* is positive, *polygonius* shows no reaction.

https://www.inaturalist.org/taxa/136972 ... wse_photos