It's not flowering because it's not getting what it needs to flower, not because it's a plant that never flowers. From the appearance of the foliage it looks like it's being kept as a house plant under ordinary indoor conditions. Moved into a brighter, more humid situation and a larger container, allowed to develop more fully it would probably soon start blooming. The commonly grown, frequently asked about Epiphyllum that produces a percentage of flattened, paddle-like stem sections is E. oxypetalum. Because this one is so prevalent chances are that is what you have. Otherwise, without the flowers having been seen it seems the plant asked about here could just as well be something else. There are many species of epiphytic cacti in cultivation including those in other genera besides the three mentioned so far here. https://www.bing.com/images/search?q=epiphyllum+oxypetalum&qpvt=epiphyllum+oxypetalum&qpvt=epiphyllum+oxypetalum&FORM=IARRSM

That's a Cyclamen - not the easiest thing to grow indoors. I've tried 2 or 3 times a few years ago. Lena

From the ediblewildfood site: "Catnip is a whitish-gray plant with an aromatic minty odor. It is a hardy, upright, perennial herb with sturdy stems covered with very fine hairs. Catnip bears heart-shaped, grayish-green leaves". From the smell I took, this plant did not have a minty odor but the description of its leaf is close. I have never seen catnip grow to this size as my cat always ate it. . The online pictures of purple sage flowers really looks like this plant. It's really 50-50 for each plant. The catnip leaf not the purple sage leaf. The purple sage flower not the catnip. Smell - up for grabs. Anyway, thanks to everyone for their input. It's either one or the other!!

Looks to me like they could be the weed yellow avens.... Botanically a geum -and the reason I never plant ornamental germs (I’d probably assume they were a weed and rip them out again!)