"Bestiarum Vocabulum: Monstrous Plants" provides gamemasters with detailed entries for a variety of deadly vegetation that can be used to enhance your next encounters. 

Despite the abundance of plants in most fantasy game settings, the green, growing world has not inspired nearly as many monstrous plant menaces as one might expect, but this is a subject ripe with potential for the truly terrifying. Monstrous vegetation and fungi might sprout from many places and causes, including manipulation by spells or curses, contamination by alchemical pollution, meddling by the divine, or even unholy hybrids involving plants or spores transplanted from other planes of existencethat then cross-pollinate with local flora.