Ridged

Anatomy and distinctive features of the ridged hymenophore

A ridged hymenophore (plicate or ridged) is a spore-bearing surface that has no separate blades (as gilled mushrooms do); instead it forms wavy wrinkles, veins or blunt folds that are an inseparable continuation of the mushroom's own flesh. M.Ya. Zerova stresses this solid, all-of-a-piece structure in her "Handbook of the Fungi of Ukraine": the ridges are thickenings of the cap and stem themselves, running smoothly and deeply down the stem.

In "Mushrooms Demystified", David Arora considers the difference between true gills and ridges fundamental knowledge for a beginner. He puts it this way: true gills look like the pages of a book glued to its cover — you can snap them off or cut them away with a knife. Ridges, on the other hand, are like wrinkles in skin; you can't separate a wrinkle from the skin itself.

In his guide "Mushrooms", Roger Phillips describes this type of hymenophore in detail using the chanterelle family (Cantharellaceae) as an example. In the true chanterelle (Cantharellus cibarius) the ridges are thick, blunt-edged, often forked (dichotomously branched) and have similar cross-connections between them. This relief can sometimes be so smoothed out that the mushroom looks almost smooth underneath.

For a forager, recognizing a ridged hymenophore is an absolute guarantee of safety when picking chanterelles. The false chanterelle (Hygrophoropsis aurantiaca) and the poisonous jack-o'-lantern mushroom (Omphalotus olearius), which grows in the south and has a similar color, have true, thin, knife-sharp gills that clearly separate from the flesh.