What You Should Know
Cortinarius orellanus is a lethally poisonous mushroom. This medium-sized agaric with tawny brown, bluntu umbonate cap. The gills are colored as the stem. Grows solitary of in scattered trooping groups, with broad-leaf trees.
This mushroom is found from late summer to early winter in woodland. Despite usually being a very different shape, the orange cap of this attractive mushroom has resulted in it being mistaken for Cantharelus cibarius, the highly prized edible chanterelle mushroom - with serious and in many cases fatal consequences.
Other names: Fool's Webcap, Poznan Cort Mushroom.
Cortinarius orellanus Mushroom Identification
The tawny-brown to reddish-orange cap is at first convex, flattening at maturity but retaining a slight umbo; its surface is dry and slightly scaly, most noticeably in the centre of the cap.
Cap diameter is typically 4 to 7cm when fully expanded, and the margin is usually rolled down.
The widely-spaced gills, which are covered by a weakish cortina in young specimens, are pale yellowish at first, becoming red as the spores mature.
The stem of Cortinarius orellanus, which is often slightly bowed rather than straight, is usually slightly paler than the cap and sometimes retains fibres from the cortina, mottled with red; it is fibrous and has a curved base that tapers in slightly.
Unlike Cortinarius rubellus, the stem of Cortinarius orellanus does not have a pronounced yellowish snakeskin-like surface pattern.
The stem is typically 7 to 15mm in diameter and 5 to 10 cm tall.
Ellipsoidal to sub-globose, 9-12.5 x 6.5-8.5μm; with a rough surface. Spore print rusty reddish-brown.
Ectomycorrhizal with hardwood trees (especially oak) and sometimes also under conifers, on both alkaline and acidic soils.
Season: August to November.
Cortinarius orellanus Toxicity
The cause of Cortinarius orellanus and Cortinarius rubellus induced kidney failure is the nondescript looking chemical orellanine. Orellanine, structurally, is a pyridine N-oxide, and exists as two tautomers. The favored tautomer is the bis-N-oxide (that’s the one on the left in the figure, below).
Another notable pyridinium is paraquat, an herbicide that kills everything green and doesn’t hold back against humans either. Despite being linked to Parkinson’s disease, it is one of the most widely used herbicides in the world. So just from a structural standpoint alone, a good chemist or pharmacologist would suspect that orellanine is up to no good.
Once orellanine had been ingested, using one of the lethal webcaps as a delivery system, the latent period before onset of symptoms is between 12 hours to 14 days, with the average being 3 days. So you are poisoned, with irreversible kidney failure in your future, but may not know it for a week.
Initial symptoms are flu-like, and include: vomiting, excessive thirst, nausea, and pain.
Cortinarius orellanus Taxonomy and Etymology
Cortinarius orellanus was described and named by the great Swedish mycologist Elias Magnus Fries in 1838. Its synonyms include Cortinarius rutilans Quel., and Dermocybe orellana (Fr.) Ricken.
The generic name Cortinarius is a reference to the partial veil or cortina (meaning a curtain) that covers the gills when caps are immature. In the genus Cortinarius most species produce partial veils in the form of a fine web of radial fibres connecting the stem to the rim of the cap rather than a solid membrane.
Photo 1 - Author: Andreas Kunze (Creative Commons Attribution-Share Alike 3.0 Unported)
Photo 2 - Author: Andreas Kunze (Creative Commons Attribution-Share Alike 3.0 Unported)
Photo 3 - Author: The original uploader was Michaelll at English Wikipedia. (Creative Commons Attribution-Share Alike 2.5 Generic)
Photo 4 - Author: Thomas Pruß (Creative Commons Attribution-Share Alike 3.0 Unported)
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