Though DAY OF THE TRIFFIDS is a silly movie on many levels (and one that Matt promises to take a more in depth look at in an upcoming article), there's some pretty landmark events in this 1963 film. For one, it's the first movie were walking plants roamed the Earth and plagued mankind. It also showcased the magical effects of a radioactive comet to make plants into killers, 5 years before NIGHT OF THE LIVING DEAD did the same thing with zombies.
TRIFFIDS is based on a 1953 novel by the same name by respected science fiction author John Wyndham. The movie turns up the camp and fun, however and really plays up these plants as great vegetable versions of zombies. Apparently they have a horrible sting, drain the life force from folks, and make this insane "POCKETA POCKETA POCKETA" sound when they walk around that's probably annoying the crap out of you right now if the background music is playing.
It turns out that everyone in the world who sees this horrible comet goes blind, which makes them easy pickings for the marauding plants (and sales for the Braille version of "Are You There God, It's Me, Margaret?" go through the roof). The hero, who luckily can see, has a final showdown with them in a lighthouse, turns on a firehose, and finds out that saltwater turns them to goo.
What the? That's not a very strong monster after all. You could basically whip out your dick and piss on these things and make them die a miserable death. After the hero radios the rest of the world and clues them in on this little fact, they're all killed in about an hour.
What's even funnier is the absolute end of the film, when the hero and his gal fly away off the island they were stranded on, to a happy ending. Only, they leave a few hundred blind people behind to fend for themselves. THANKS, ASSHOLE!
The BBC also made a TV miniseries of this in 1981 that was a bit more faithful to the original novel.
Though Triffids are easily killed with seawater, at least they weren't vanquished with Slim Whitman music, ala MARS ATTACKS!