In response to Weiliiiiiii: There are about 30 taxa in sect. Caesareae in the U.S. and Canada (with at least another half-dozen in Mexico…probably an underestimate). About half are unnamed. The species of the Caesareae known from the eastern U.S. and Canada include
1. Amanita arkansana Rosen. 1926.
2. Amanita banningiana Tulloss. nom. prov.
3. Amanita calyptrata var. albescens Peck. 1900.
4. Amanita chambersiana Tulloss nom. prov. (recutita sensu Coker. 1917.)
5. Amanita cinderellae Tulloss nom. prov. (Amanita species N4)
6. Amanita cokeriana Singer. 1948.
7. Amanita jacksonii Pomerleau. 1984.
8. Amanita murrilliana Singer. 1950 [“1949”].
9. Amanita pachysperma G. F. Atk. 1918.
10. Amanita spreta (Peck) Sacc. var. spreta. 1887.
11. Amanita spretella (Murrill) Murrill. 1948.
12. Amanita subvirginiana (Murrill) Murrill. 1941.
13. Amanita virginiana (Murrill) Murrill. 1914.
14. Amanita species 53 (“Londo Mollari’s Slender Caesar”)
15. Amanita species AR1
16. Amanita species F2
17. Amanita species F10
18. Amanita species F11
19. Amanita species F16 (“Tequila Sunrise Slender Caesar”)
20. Amanita species ONT1
21. Amanita species QUE1
22. Amanita species S10
23. Amanita species T24
24. Amanita species T31
25. Amanita species T41
26. Amanita species V2
There are more in the western part of the US. So far as it is known, the western taxa do not include species in stirps Hemibapha (the “Slender Caesars”).
The codes beginning with “T” are explained to some degree in the east Texas and Gulf Coast checklist. Many of the above “numbered” taxa are included in the key to the Caesareae that is found on the Amanita Studies web site. The omissions in that key will be entered as soon as I can do so.