Key to the species of Volvopluteus

1. Stipe shorter, <4 cm in length, with distinct grooves ...................................................................................................... V. canalipes

1. Stipe longer, ≥ 4 cm in length, glabrous.............................................................................................................................................2

2. Pileus <5 cm in diameter, stipe <8 cm in length ..............................................................................................................................3

2. Pileus ≥ 5 cm in diameter, stipe ≥ 8 cm in length...............................................................................................................................4

3. Basidiospores smaller (11–16 × 8–11 μm), pleurocystidia absent, and cheilocystidia present.............................................. V. earlei

3. Basidiospores larger (16–18 × 9.5–11.5 μm), pleurocystidia present, and cheilocystidia absent ...................................... V. platensis

4. Basidiospores length <14.5 μm ..........................................................................................................................................................5

4. Basidiospores length ≥ 14.5 μm .........................................................................................................................................................7

5. Pileus with dark blonde center when mature................................................................................................................ V. yunnanensis

5. Pileus gray to brownish gray when mature ........................................................................................................................................6

6. Margin of pileus rimose, volva height <1.5 cm ........................................................................................................ V. michiganensis

6. Margin of pileus not rimose, volva height ≥ 1.5 cm ........................................................................................................... V. asiaticus

7. Pleurocystidia absent .......................................................................................................................................................... V. longipes

7. Pleurocystidia readily observable.......................................................................................................................................................8

8. Basidia smaller (22–35 × 7–13 μm) .......................................................................................................................... V. gloiocephalus

8. Basidia larger (42–65 × 13–16 μm).................................................................................................................................. V. deliciosus