Created: 2007-10-12 08:22:01
By: Rod Tulloss (ret)
Summary: Not the European species...probably...

What I know of (this is a serious caveat) that is called “Amanita caesarea” in Arizona is related to the calyptroderma complex in the coastal states. Amanita caesarea has a deep subhymenium of inflated cells, which is a character I used to define Amanita stirps Caesarea in the group of “caesar-like” amanitas. There are at least three other groups: One has a shallow subhymenium of inflated cells, has small fruiting bodies, and has plentiful 2-spored basidia (e.g., A. ristichii). One has moderate to large fruiting bodies, a shallow subhymenium of inflated cells, and 4-spored basidia. One has a subhymenium of branching and, usually, not strongly inflated cells (calyptroderma group). Alexander Smith was aware of the latter group as can be told from his notes on microscopic examination of Arizona and New Mexico material sent to him by Barrows.