Reddit user Independent-Design17 proposed a fascinating connection between Elden Ring's Erdtree and the Australian Christmas tree, Nuytsia floribunda. Superficial similarities exist, particularly when comparing the in-game "Small Erdtrees" to the Nuytsia. However, the parallels run deeper.
Elden Ring lore depicts the Erdtree as a guiding force for the souls of the deceased, reflected by the game's catacombs at its base. Intriguingly, Nuytsia floribunda holds similar spiritual significance in Australian Aboriginal culture. Each flowering branch is seen as representing a departed soul, and its vibrant color is linked to the sunset, the perceived destination of spirits.
Further strengthening the comparison is the semi-parasitic nature of Nuytsia. This tree draws nutrients from surrounding vegetation. This resonates with a popular fan theory suggesting the Erdtree is parasitic, having usurped the life force of an ancient Great Tree. However, it's now understood that in-game references to a "Great Tree" are a mistranslation, actually referring to the Erdtree's own extensive root system.
Ultimately, whether FromSoftware intentionally drew inspiration from Nuytsia floribunda remains a mystery, known only to the developers.