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 depiction of smaller Erdtrees. However, the parallels run deeper.
Elden Ring lore suggests the Erdtree guides the souls of the deceased, reflected by the catacombs at its base. Intriguingly, Nuytsia floribunda holds similar spiritual significance in Aboriginal Australian culture. Each flowering branch represents a departed soul, and its vibrant color is linked to the sunset, the believed destination of spirits.
Further strengthening the comparison is Nuytsia's semi-parasitic nature; it draws nutrients from neighboring plants. This resonates with fan theories suggesting the Erdtree is parasitic, having overtaken the roots of an ancient Great Tree, the original source of life. However, it's now understood that game item descriptions referencing a "Great Tree" are mistranslations, actually referring to the Erdtree's own extensive root system.
Ultimately, only FromSoftware knows if these striking parallels to Nuytsia floribunda were deliberate or coincidental.