Classic TV - Tales of Tomorrow - "The Fatal Flower" (1952)

A botanist breeding a monstrous carnivorous plant spars with his assistant, in the isolation and oppressive heat of their research compound in a remote sector of the Amazon. Dr. Alden's gleeful obsession with his hybrid plant buoys him along, until his aide Merriman's boredom inspires a means to play on the older man's weak heart and narrow mind.
https://www.imdb.com/title/tt0717063/plotsummary?ref_=tt_ov_pl

This video is in the Public Domain.