Amanita fernandeziana

The following is based on the description by Singer (1959a).  Singer was working from a dried specimen and, hence, the provisional nature of the name.

The cap of A. fernandeziana is 32 mm wide, brown as dried, but may have originally been white; it is smooth all over, with a nonstriate margin.  The cap lacks pyramidal or otherwise conspicuous warts. The cap reportedly lacks a well-developed pileipellis.

The gills are free or subfree, subclose, and brownish, obviously white when fresh, and rather broad.  The short gills are truncate.

The stem is 22 × 6 mm, probably white when fresh, smooth, glabrous, equal, bearing some fragments of an annulus, and lacking remnants of a volva in the dry material.

The spores measure 9.3 - 12 × 7.5 - 9 µm and are amyloid and short ellipsoid to subglobose.  Clamps are absent at bases of basidia.

Amanita fernandeziana was described provisionally from Masatierra (aka Robinson Crusoe) Isl., Juan Fernandez Islands, Chile; and it is still known only from the single collection.

Associated vegetation was not recorded by the collector of the single specimen seen by Singer.  However, Singer notes that the major ectomycorrhizal symbiont of Amanita on the mainland of Chile and Argentina is Southern Beech (Nothofagus), and that that genus is absent on the island where the single specimen of A. fernandeziana was found.

Why would this specimen be catalogued in section Lepidella rather than in Amanita sect. Validae (Fr.) Quél.? Assuming the accuracy of the report of the amyloid reaction of the spores, the absence of volval remnants of any kind, and omission of mention of a bulbous base in the dried specimen, it is reasonable to eliminate sect. Phalloideae (Fr.) Quél. (of which only one native taxon and one introduced taxon are known from the southern cone of South America) and section Amidella (E.-J. Gilbert) Konrad & Maubl. (of which no taxa are reported from the entire continent).

This then leaves sections Lepidella and Validae to be considered.  The former has an entire subsection ( Amanita subsect. Vittadiniae Bas) with undeveloped or poorly developed skin on the cap (pileipellis). Species of this section are often reported to occur without woody symbionts in evidence.  About half of all native Amanita taxa reported from Argentina fall into subsection Vittadiniae.  On the other hand, section Validae has no known taxa with this character.  Moreover, there is a single species of section Validae known from the southern cone and it is not native.  Hence, there is a supporting argument for the provisional placement of the provisionally named A. fernandeziana in section Lepidella.

Recent studies from Chile have reported on inamyloid-spored species from native forest and species from introduced pine plantations; possibly as a result, we know very little of native amyloid-spored taxa from the Chilean mainland.  Off-prints that would help improve this perception are welcomed by the editors. —R. E. Tulloss

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