As early as 1940 comic book writers and artists have used the killer plant in their comics. Why not? Vines are easy to draw. Many superheroes have faced off against killer trees, poisonous femme fatales and slime beasts. The horror anthologies loved to have retribution come in the form of flower, barbarians like Conan and Arak faced off against lethal vegetation and monsters like Godzilla need bigger and bigger opponents. Groot, perhaps the most popular plant character today, started as a one-shot horror piece by Jack Kirby. You just never know who the next big plant will be.
The funny thing about all these plants comics is the prevalence of the May date on the covers. It is like the publishers know when allergy season will fuel sales. Green plants and greener noses.
For more on Plant monsters, check out my piece, “Turok, Son of Plants”.