Sure these yellow-eyed blooming grasses look innocent enough. But if you look more closely, you may just find yourself actually staring at the fungus Fusarium xyrophilum which is reported to infect two types of yellow-eyed grasses (X. setigera & X. surinamensis) growing on the savannas of Guyana rather than at an actual blossom. The Xyris genus counts over 250 species and is widespread throughout much of the world.
Is there a trickster in the grasses?
What a trickster this fungus is! It creates structures known as pseudo-flower formations that, according to The Guardian, “are a similar size and shape with petal-like features that reflect ultraviolet light to attract pollinators, especially bees ... and even use fragrances to make themselves even more attractive.”
In Defense of Plants blog notes that "This species of Fusarium cannot exist without its Xyris hosts. However, Xyris don’t live forever and for the cycle to continue, Fusarium must go on to infect other Xyris individuals." That is where the bees and other pollinators come in.
When pollinators cozy up to the bogus flowers, they become coated with spores from the fungus and “unwittingly carry them off to other Xyris plants and infect them.” As a Smithsonian Magazine article about the fungus points out “the anticipated meal of nectar and pollen is replaced by a face full of spores.” Thankfully, there is no evidence that these fungal spores harm the unsuspecting pollinators.
According to Kerry O’Donnell, a microbiologist at the U.S. Department of Agriculture’s Agricultural Research Service and co-author of the research, “This is the only example that we know of, anywhere on planet Earth, where the false flower is all fungal.”
It seems as if the fungal world is always gifting us with something new under the sun!