Opuntia argentiniana
Argentina Cactus
Fertilization for Young Plants
Young plants need extra phosphorus to encourage good root development. Look for a fertilizer that has phosphorus, P, in it(the second number on the bag.) Apply recommended amount for plant per label directions in the soil at time of planting or at least during the first growing season.
Source: Backyard Gardener
Scientific classification
Kingdom: Plantae
Clade: Angiosperms
Clade: Eudicots
Order: Caryophyllales
Family: Cactaceae
Subfamily: Opuntioideae
Tribe: Opuntieae
Genus: Opuntia
– Wikipedia.