The root bulbs on a spider plant are called tubers or tuberous roots. These thick, fleshy, white structures are part of the root system and function primarily to store water, allowing the plant Amazon.com : Hymenocallis 'Tropical Giant' is Often Called a 'White Spider Lily' and is Versatile and Cold Hardy as it Blooms in Late Summer 2 Small Bulbs : Patio, Lawn & Garden Can spider plants be in direct sunlight outside? Unicorn Plants Plant Vault Philodendron 'Ring of Fire' Plant Care 101