I'll try to clarify.
I pollinated my Chamaecereus silvestrii (mother), with the plant you see in the first picture, which i thought was a botanical species (Lobivia sublimiflora).
I obtained 7 plants whose body looks identical, which seemed to confirm the hypothesis (the F1 from two botanical species should look pretty much the same).
But then they started to flower and showed different characteristics: different petals shape...
Enrico This made me wonder if the father was really a pure botanical species.
The most striking for me was the second child; so I was asking if this variation was a symptom of an hybrid parent.
My knowledge in the hybrid field is mostly theoretical, it is the first time I had a number of plants to compare.
muddyliz I will wait for the plant with the fuzzy flower to mature.
I will be more cautious with my conclusions.
By the way, yesterday another one flowered.

Many thanks,
Fabio
P.S. this thread is becoming more on the hybrids than on the parent plant... maybe is becoming off topic in this section.