Pored

Anatomy and classification of the pored hymenophore

A pored hymenophore (poroid / tubular) is made of a mass of vertical tubes packed tightly together, inside which the hymenium develops and the spores ripen. The open lower ends of these tubes form the pores we see with the naked eye. In her "Handbook of the Fungi of Ukraine", M.Ya. Zerova notes that this structure is typical of two large but ecologically different groups of macrofungi: the fleshy boletes (Boletales) and the tough, wood-decaying polypores (Polyporales).

In "Mushrooms Demystified", David Arora highlights a key anatomical detail of fleshy boletes (porcini, aspen boletes, slippery jacks): their tube layer can easily be peeled away from the cap flesh in a single sheet. In polypores that grow on trees, by contrast, the tubes are firmly fused with the tissue of the fruiting body and won't come apart.

In his guide "Mushrooms", Roger Phillips pays special attention to the color of the pores and how they react to damage. This is a critical factor in identification. The tubes can be white, yellow, olive or red. Pressing a finger on the pore layer of many pored mushrooms (for example, lurid boletes or the cornflower bolete) causes instant, dramatic bluing — an oxidation reaction that scares beginners but is a perfectly normal species trait.

For a forager, a pored hymenophore (a sponge) is a byword for high safety. In the forests of Europe there is not a single deadly poisonous mushroom (like the death cap) with a tube layer. The worst that can happen if you make a mistake is picking a bitter bolete (Tylopilus felleus) with pink pores, which will ruin a dish with its unbearably bitter taste, or poisoning by the devil's bolete, which causes severe stomach upset but is rarely fatal.