Emerges from roots looking exactly like a brown mushroom cap. Only DNA analysis revealed it's a flowering plant. Convergent evolution creating plant fungi that fool botanists.
Denis Zabin, CC BY 4.0, via Wikimedia Commons
The Plant That Forgot It Was a Plant
On the floor of Brazil's Atlantic forests, a strange organism pushes up through the leaf litter. It has no green parts, no leaves, and its fleshy, rounded form looks for all the world like a fungus. This is Scybalium fungiforme, a name that literally means "fungus-shaped." For a long time, its appearance fooled observers. It belongs to the Balanophoraceae, a family of bizarre flowering plants that have abandoned photosynthesis entirely.
Scybalium fungiforme is an obligate holoparasite. This means it spends almost its entire life underground as a lumpy, tuberous structure fused to the roots of a host plant, siphoning off all the water and nutrients it needs to survive. The plant lacks chlorophyll and has no root system of its own, instead using a specialized organ called a haustorium to penetrate its host. This parasitic lifestyle has led to the loss of typical plant features, a example of convergent evolution where it has evolved to resemble the fungi that share its dark, subterranean habitat. Its main hosts are fast-growing lianas and a pioneer tree species, Croton floribundus. The visible "mushroom" is actually a dense inflorescence—a structure packed with tiny, unisexual flowers that can reach about 8 cm in diameter.
An Opossum's Secret Garden
The floral structure of Scybalium fungiforme presents a puzzle. The nectar-rich flowers are hidden beneath tough, scale-like bracts, making them inaccessible to most insects. In the 1990s, botanist Patrícia Morellato theorized that a mammal with dexterous hands might be important. Her hypothesis was based on pollination syndrome—the idea that a flower's traits reflect its primary pollinator. The flower's low-to-the-ground position, copious nectar, and tough covering all pointed to a non-flying mammal.
Decades later, in 2019, night-vision cameras finally confirmed her prediction. The footage captured big-eared opossums (Didelphis aurita) methodically using their opposable thumbs to peel back the bracts, push their faces into the inflorescence to drink the nectar, and emerge with pollen-dusted snouts. As the opossums move from one plant to another, they achieve pollination. Once the bracts are removed, a host of secondary pollinators can access the now-exposed flowers, including bees, wasps, hummingbirds like the Violet-capped Woodnymph (Thalurania glaucopis), and even the montane grass mouse (Akodon montensis). This complex web of interactions, with an opossum as the primary facilitator, is a pollination strategy that took nearly 30 years to prove.
💡Fun Facts
The plant's Latin name, *fungiforme*, explicitly means "fungus-shaped," acknowledging its deceptive appearance.
The big-eared opossum (*Didelphis aurita*) is the primary pollinator, using its unique opposable thumbs to access the nectar.
As a holoparasite, it has no chlorophyll and lives almost entirely underground attached to the roots of host trees and lianas.
Once an opossum opens the flower structure, secondary pollinators like hummingbirds, bees, and even mice can also access the nectar.
