Parasitic flowering plant fertilizes itself while feeding off fungi

The flora and fauna of Japan have been studied and cataloged extensively, so it was a bit of a surprise when a new species of plant was recently announced. It makes a bit more sense though, when you consider just how little Gastrodia kuroshimensis resembles the average flowering plant— it doesn’t produce chlorophyll, leaving it a pale brown instead of green, and while it does bud, those buds never open into flowers. Native to the small island of Kuroshima, the thick stalks poking above the leaf litter end up looking a bit like a dead stalk, rather than a living parasite.

Ignoring sunlight and growing non-flowering flowers is certainly odd, but while G. kuroshimensis stands out for combining both counterintuitive strategies, they have been seen in other species. Plants that skip growing chlorophyll for photosynthesis fall into two categories, although both effectively function as parasites. Haustorial parasites leach nutrients directly off the roots of other plants, while mycoheterotrophic epiparasites draw nutrients from a fungus that is attached to another plant’s roots. G. kuroshimensis falls into the latter category, deriving all its nutrients from fungi preying on other plants.

Not quite fruitless flowers

With food sourced underground, it’s all the weirder that G. kuroshimensis bothers sending any anatomy above the leaf litter at all. It does bother to sprout cleistogamous flowers, although the buds never actually open. This means that rather than allow for sexual fertilization with other plants and keeping up genetic diversity, G. kuroshimensis instead effectively fertilizes itself. Risking becoming a bit of a genetic cul-de-sac, cleistogamous flowers pass down two sets of maternal genes to their offspring. This reproductive strategy is thought to be effective if the local environment is stable, but may be problematic if there are changes in climate or the food chain. Cleistogamous flowers don’t need to sprout near other members of the same species, but they also can’t adapt to change as quickly as other plants.

At this point, it’s unclear how these two, rather picky traits came together in a single plant that seems to defy most people’s concept of flowering plants in the first place. Researchers plan to investigate further, hoping that some gene or element of the island’s ecology will help explain how these limiting traits arose in the first place.

Source: Plant discovered that neither photosynthesizes nor blooms, Scienmag