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Hymenophore

Spiny

Spines — mushrooms with the trait «Spines»

Peeking under the cap of a forest mushroom, you may be surprised to find a mass of soft, hanging spines instead of the usual gills or pores. This is a spiny hymenophore — one of the most original and easily recognized spore-bearing structures in the fungal kingdom, and a reliable marker for identifying a whole range of delicious species.

6 species in the database.

The anatomy and evolution of spines

A spiny, or hydnoid, hymenophore is characterized by vertical, cone-shaped or cylindrical outgrowths (spines or "teeth") that densely cover the underside of the cap or the whole fruiting body and hang tips down. M.Ya. Zerova explains in «Key to the Fungi of Ukraine» that the hymenium covers the entire outer surface of each spine. This structure is an effective alternative to gills and tubes for increasing the spore-bearing area.

David Arora notes in «Mushrooms Demystified» that spiny mushrooms (traditionally known as "hedgehogs" or "tooth fungi") are not a single taxonomic group. Evolution created this type of hymenophore in parallel in quite different orders. The main macroscopic representatives are the genera Hydnum (hedgehogs), Hericium and Sarcodon.

Roger Phillips in his guide «Mushrooms» focuses on how fragile this structure is. In most spiny mushrooms the spines snap off very easily at the touch of a finger, leaving smooth bare patches on the cap. For example, in the popular wood hedgehog (Hydnum repandum) the spines are pale and brittle, while in the striking lion's mane (Hericium erinaceus), which grows on trees, they are long, cascading, white and look like a waterfall of icicles.

For a forager, finding a mushroom with a well-defined spiny hymenophore is great news. Among macrofungi with long, freely hanging soft spines there is not a single poisonous species. All of them are considered safe, and many are highly prized by cooks (hedgehogs) or even have proven medicinal potential (Hericium).

Questions and answers

How is a spiny hymenophore different from a toothed one?
A spiny hymenophore consists of regular, elongated spines that are round in cross-section and hang freely downward. A toothed hymenophore usually looks like short, flattened, irregular tears in the tissue or serrated gill edges.
How can you be sure it's a wood hedgehog (Hydnum repandum) and not a chanterelle?
These mushrooms often grow side by side and have the same yellow-orange cap color. The only difference is the hymenophore. Turn the mushroom over: a chanterelle will have thick, forked ridges, while a wood hedgehog will have dense, short, easily detached spines. Both are excellent edible species.
Are there poisonous mushrooms with spines under the cap?
No, no deadly poisonous species have been recorded among the classic spiny macrofungi of European forests. Some species (for example, old specimens of Sarcodon imbricatus) may be inedible because of strong bitterness or extremely tough flesh, but they are not toxic.
Why do the spines fall off in the basket?
The spines are a very fragile anatomical structure. During transport they easily rub against each other and break. That's exactly why many cooks deliberately scrape the spines off hedgehog mushrooms with their fingers before cooking, so they don't turn to mush in the pan.

Sources

  1. 1.Зерова М.Я. та ін. Визначник грибів України. 1979
  2. 2.Roger Phillips. Mushrooms (Roger Phillips)
  3. 3.David Arora. Mushrooms Demystified
  4. 4.Index Fungorum