Reddit user Independent-Design17 proposed a fascinating theory: Elden Ring's Erd Tree draws inspiration from Australia's Christmas tree, Nuytsia floribunda.
Superficial similarities are undeniable, particularly when comparing the game's smaller Erd Trees to the Nuytsia. However, fans have unearthed deeper connections. In Elden Ring, the Erd Tree guides the souls of the departed, reflected by the game's catacombs at its base. Similarly, Aboriginal Australian culture reveres Nuytsia as a "spirit tree," its blossoms representing the souls of the deceased, their vibrant hues echoing the sunset – the spirits' purported destination.
Further bolstering this connection is Nuytsia's semi-parasitic nature; it thrives by absorbing nutrients from neighboring plants. This resonates with a prevalent fan theory suggesting the Erd Tree is parasitic, having usurped the life force of an ancient Great Tree. Interestingly, however, references to a "Great Tree" in the game's item descriptions appear to be a translation inaccuracy, referring instead to the Erd Tree's own vast root system.
Ultimately, whether these striking parallels are deliberate or coincidental remains a mystery, known only to FromSoftware.