Amanita biovigera

The original description of this fungus includes by reference the Latin description of Bresadola entitled "Amanita strangulata Fr." which is the only physical description available. It was accompanied by a watercolor the color of which does not closely match the color given in the physical description, but this may be due to the quality of the reproduction which is very grainy. Because of the brevity of the original description, the unpublished notes of Bas (in Netherlands National Herbarium in Leiden) on the material he designated as the type of A. biovigera become very important and with the exception of dimension and color, we have relied a great deal on these notes.

The cap of A. biovigera is 80 - 100 mm wide, olivaceous gray-brown, campanulate to expanded, sometimes with a depressed center containing a low broad umbo, subviscid, with a sulcate-striate margin. Volval remnants are pallid and felted. The flesh is pale. [Note: The cap color was also recorded on the label of one of Bresadola's collections as "Pileo alutaceo"-- cap tan. In addition, Bas reports the intensity of the color of the cap in the dried condition becomes paler notably from the center to the margin.]

The gills are adnate to free, crowded, rather narrow, pallid, sometimes with a dark edge. The watercolor shows the short gills to be truncate.

The stem is 120 - 160 × 11 - 15 mm, tapering upward, stuffed to hollow, dark umber brown, slightly dark umber scales in the lower part in a zebroid pattern, fibrillose in the upper part (the illustration does not indicate a pigment), with an attenuate base, with rather small fragments of the volva at the stem base (In the illustration the fragments can range from cupulate to rather large, flaring, and very irregular). The stipe flesh is pale.  No ring is present.  The volva is free, saccate, irregularly lobed, pallid on the outer surface, umbrinous on the inner surface.

The taste is said to be pleasant. Odor is said to be undetectable.

According to the original description, the spores measure 12 - 14 × 9 - 11 µm.

Spore measurements (by Dr. C. Bas) from three specimens collected by Bresadola including the proposed type are as follows: (10.8-) 11.2 - 13.9 (-14.4) × (8.2-) 8.3 - 11.5 (-11.7) µm and are broadly ellipsoid to ellipsoid, occasionally subglobose, and inamyloid.  Clamps are absent at bases of basidia.

This species was originally described from Italy.  Its habitat is unknown.

Contrary to its name, the present species predominantly bears four spores per basidium. Apparently Singer had confused material of A. pachysperma G. F. Atk. with Bresadola's description and painting. In the Farlow Herbarium (Harvard Univ.), there are a number of collections marked "A. biovigera" in Singer's hand.  These collections are in fact A. pachysperma.  A. pachysperma does have a large number of two-spored basidia in most specimens.

This species has rarely been discussed. We have extracted information from Dr. Bas' review of the type material and made it available to the public for the first time on this web page. This species appears to us to be related to Amanita malleata (Piane ex Bon) Contu and Amanita dryophila Consiglio & Contu. In reviewing the existing data in the preparation of this page, it struck us that Amanita biovigera may be a taxonomic synonym of A. dryophila. For example, in one photograph of A. dryophila in its original description, the cap color is a rather intense brown becoming orange brown away from the center with a very pale margin; in another photograph, the cap ranges from tan to orangish-tan over much of the cap in immature material. We cannot help but note that Bresadola's material that was labeled "juvenilis" (immature) is the material also labeled "Pileo alutaceo" (cap tan).  If synonymy were demonstrated, the name with priority is Amanita biovigera.—R. E. Tulloss and L. Possiel

The editors of this site owe a great debt to Dr. Cornelis Bas whose famous cigar box files of Amanita nomenclatural information gathered over three or more decades were made available to RET for computerization and make up the lion's share of the nomenclatural information presented on this site.