Plants that eat... plants?

There's a good chance that you've heard of Rafflesia spp. plants. They're often cited as having the largest flowers in the world, which is true depending on the perspective you're taking. They're also known for smelling like a dead possum you'd pull out from under you deck after wondering what that smell was for 3 days, yummy! Oh, and if you were a nerdier kid you'd probably recognize that the Pokémon Vileplume was inspired by their enormous petals:

Rafflesia arnoldii on its host vine,  Tetrastigma sp.

Vileplume from Pokémon

Now, even if you knew about Rafflesia, you probably didn't know that it's actually a holoparasite, i.e., it exclusively receives its nutrients from a host. In other words, this is a plant that forgot how to be a real plant: it cannot photosynthesize. They exist, rather, more like fungal mycelium nestled amongst the fibers of host Tetrastigma vines (which are in the same family as grapes) in thin strands of cells that are quite lackluster. That is, until they decide to bloom. 

    Jeanmaire Molina, an evolutionary plant biologist, was the one to find out that these plants in the Rafflesiaceae family have completely ditched any functional chloroplast genes. A team at Harvard uncovered in a closely related species, Sapria himalayana, that these plants have shed all photosynthetic capacities in order to be more efficient parasites, outsourcing the labor of metabolic processes to their hosts. Hauntingly, 1.2% of Sapria's genome comes from hosts of Christmas past and present (which is bigger than it sounds given these are complex eukaryotes here). Their genome has been described as a "huge graveyard of DNA" by Liming Cai, a systematic biologist postdoc. Also, like 60% of these things' genome is repeating retrotransposons, but no one really knows what that's about yet. All in all, they have evolved exclusively to get really good at schmoozing their hosts out of their hard-made food and then making one hell of a scene when they're ready to get some.

To summarize, some of the largest flowers in the world are made by plant vampires. Sleep well! :)

Thanks for reading!

P.S. if you're interested in more parasitic plants, One-Flower Indian Pipe (Monotropa uniflora) are native (albeit, rare) to the Eastern part of Kansas :)

Resources:

Article by Quanta Magazine: https://www.quantamagazine.org/dna-of-giant-corpse-flower-parasite-surprises-biologists-20210421/