Just the thing for a dull Monday, Plant Monsters of Amazing Stories and Plant Monsters of Astounding. Both new illustrated surveys by G.W. Thomas at Dark Worlds Quarterly, with his survey of Thrilling Wonder Stories still to come.
There was also a survey of Plant Monsters in Weird Tales back in 2020, and a brief look at The Earliest Plant Monsters in 2019. Also to be found at Dark Worlds are various surveys of the subject in pre-Code comics.