[marcellocatalano]

Exactely. Unfortunately it's impossible to distinguish a pure globosa from a globosa x mirabilis. That's why it's useless and dangerous to make this hybrid in cultivation just for fun or because someone had mirabilis and globosa flowering together. The main globosa feature is the very variable position of the pitcher hip, which gives the pitchers their typical globose shape. The pitcher hip in globosa can vary from being absent to be just above the midline. Differently from what many people think, the fact that the hip on a globosa plant is just above the midline, doesn't mean it's a hybrid with mirabilis. It just belongs to the normal range of variability of globosa in the wild, in both Phang-nga and Trang, the two provinces where this taxon grows. In Phang-nga, globosa and mirabilis can grow side by side, occupying different ecological niches and remaining separate taxa, and of course, even there, globosa has a variable pitcher hip. At that point it's impossible to know if a particular plant with a pitcher hip just above the midline is a (rare?) mirabilis x globosa backcross or a just a variable globosa. In Trang the two taxa don't grow together, and yet you have the same variable pitcher hips in globosa.
There are other small features typical of globosa (to read the description on my website, click on my signature), but they are hard to use to split a hybrid from a pure globosa. Usually in cultivation globosa and mirabilis x globosa are labelled correctly anyway, so if you bought your plant as globosa, it should be globosa.

About the hybrid with ampullaria, don't just check for any indumentum in general, because even mirabilis and globosa are hairy. You should check for the typical indumentum of ampullaria. Even better, just check the leaf base on the climbing stem (at the rosette level, all species look the same), because ampullaria and globosa/mirabilis are very different.