1	"Stigma lobes white to yellow "	2
1	"Stigma lobes orange, pink, red or purple "	8
2	"Body extremely small, mostly much less than 4 cm wide and without ribs, tubercles or spines "	"Parodia liliputana"
2	"Body not as above "	3
3	"Ribs vertical, distinct; flowers more than 4.5 cm wide "	4
3	"Ribs spiralling, indestinct or formed of tubercles; flowers often more than 4.5 cm wide "	6
4	"Ribs 11–16 "	"Parodia magnifica"
4	"Ribs more than 20 "	5
5	"Spines 6–11 per areole "	"Parodia schumanniana"
5	"Spines more than 18 "	"Parodia leninghausii"
6	"Pericarpel with dense white or brown wool largely concealing the few bristles; (bristles on most scales of flower tube, ribs spiral, flowers mostly yellow) "	"Parodia chrysacanthion"
6	"Pericarpel, tube and fruit with bristles and wool "	7
7	"Flowers red, stamens concealed by perianth "	"Parodia haselbergii"
7	"Flowers yellowish, stamens apparent "	"Parodia graessneri"
8	"Ribs shallow and rounded; flowers of 1 colour "	9
8	"Ribs more than 5 mm tall with sharp ridge; flowers; of 1 or 2 colours "	10
9	"Stems slightly flattened spines mostly less than 15 per areole; flowers purple, white or yellow "	"Parodia crassigibba"
9	"Stems spherical or cylindrical; spines about 20–40; flowers bright yellow "	"Parodia scopa"
10	"Flowers magenta with pale or yellow throat (ribs less than 5 mm deep) "	"Parodia rutilans"
10	"Flowers of 1 colour "	11
11	"Spines flexible, flowers pale orange "	"Parodia horstii"
11	"Spines rigid "	12
12	"Body dark green; spines at least 8 per areole, ribs mostly 15–25 "	"Parodia mammulosa"
12	"Body mostly grey-green to waxy blue; spines to 8 per areole, ribs "	"Parodia buiningii"