| name | Amanita sp-AZ18 |
| name status | cryptonomen temporarium |
| author | Tulloss |
| images |
 1. Amanita sp-AZ18, Chiricahua Mtns., Cochise Co., Arizona, U.S.A. |
| intro | The following is based on original research of R.E. Tulloss. |
| cap | The pale yellow to brown cap is 30-78 mm wide and sometimes has a brownish gray ring on the grooved edge. The center of the cap is faintly yellow-brown to pale pink and sometimes is faintly streaked radially when viewed with a 10× lens. The cap is bell-shaped to slightly convex with a distinct broadly rounded knob. The cap's flesh is white to off-white and there is a gray line where the gills attach. The flesh is 4 - 7.5 mm thick above the stem, thins evenly for most of the radius, and then is membranous to the edge. The cap's edge is grooved and volval remnants are absent. |
| gills | The off-white to cream gills are free and rather distant from the stem and are connected to the top of the stem by faint descending lines on the upper stem. They are close to crowded, 5 - 5.5 mm broad, and infrequently fork or form traverse connections. The unevenly distributed short gills are cut off squarely, are of diverse lengths, and are plentiful. |
| stem | The pale gray to off-white stem is 117 - 120 x 10 - 12.5 mm and becomes faintly yellow- brown when handled and with age. The stem narrows upward and flares somewhat at the top. At first the top of the stem is decorated with fine tufts and the bottom is silky and shiny; with age the stem becomes bald with a few fibers in the lower half. The stem's flesh is white to pale cream, and is faintly gray at the base of the stem where it attaches to the volva. The stem is stuffed loosely with white fibers in a central cylinder 3 - 4.5 mm wide. The volva is saclike and tube-shaped with many yellow-brown spots and stains on the lower half of the outside. The volva is white on its interior surface and is 48 - 60 x 19.5 - 28 mm and up to 1 mm thick. A small internal limb (often disappearing in age) is present just above the point of attachment of the volva to the stem. |
| odor/taste | The odor of this mushroom is not distinctive. The taste has not been recorded. |
| spores | The spores of this mushroom are (10.5-) 10.8 - 13.5 (-16.5) × 10.0 - 12.5 (-14.2) µm, inamyloid, and globose to subglobose. Clamps are probably rare or absent at bases of basidia. |
| discussion | This species were found growing solitarily at an elevation of 2500 m in loam and litter under varied Fir species including White Fir (Abies concolor), Aspen (Populus tremuloides,), Douglas Fir (Pseudotsuga menziesii ), and Arizona Pine (Pinus arizonica). Of the Arizona code-named taxa, this appears to be most similar to Amanita sp-AZ03.—R. E. Tulloss and N. Goldman |
| brief editors | RET |
Spore data sets and their composite