BRIEF DESCRIPTION: The cap of Amanita colombiana may be free of volval remnants, but it usually bears easily broken, crushed, or removed volval warts that are red at first, and then become gray. The discoloring volva suggests a realtionship with the Old World species A. ceciliae (Berk. & Broome) Bas; however, A. colombiana is the only known species of the "ceciliae group" that has a red volva. The cap is 20 - 55 mm wide, with the center somewhat depressed at maturity, and with a strongly striate margin; it is dull olivaceous, brownish gray or olivaceous grayish brown.

The gills are free, subdistant, white in mass, not noticeably discoloring, and 4 - 6 mm broad, gray-marginate at maturity; the short gills are truncate, of varying length, and numerous.

The stem is 75 - 80 × 5 - 6 mm>, predominantly white, and exannulate, with patches of the easily breakable volva at the base. The volva on the stipe is colored like that on the cap and becomes sordid with age also.

The spores measure (9.0-) 10.0 - 12.8 (-14.5) x (8.5-) 9.5 - 12.0 (-14.0) µm and are globose to subglobose (rarely broadly ellipsoid) and inamyloid. Clamps are absent from bases of basidia.

The species occurs in montane Oak (Quercus) forest.

Amanita colombiana was originally described from Colombia (1992). It is known from Costa Rica to Andean Colombia. -- R. E. Tulloss