so I recently bought this tiny set of succulents. I know that the two on the edge are cacti but i do not know the species. the one on the midle is something i cant figure out if it is a cactus or a succulent. can you help me figure out its species, it would definitely be very helpful. thanks
Left: Mammillaria vetula ssp. gracilis. Centre: Difficult to tell, I would need closeups of both the upper and lower stem segments. Right: Too small, columnar cacti are not easy to identify at that size. Perhaps a 'Fairy castle' (Acanthocereus tetragonus)?