The Red Weed (a.k.a. Red Creeper) is a type of vegetable life indigenous to the planet Mars. Although normally red in color as its name would imply, it is also noted as glowing with a violet-purple fluorescence at night. It appears to be safe to eat, although the taste is described as sickly and metallic.
During the Martian invasion of Earth at the turn of the twentieth century, this species was introduced to Earth either intentionally or by accident and briefly became an invasive species, growing out of control in and around the Thames and anyplace with abundant water. Its rapid growth caused it to clog rivers and waterways with extreme ease. After an initially explosive growth, however, the weed seems to have been unable to adapt to Earth ecology and died out, quite probably from microbial infection much like the Martians themselves.
- The Crystal Egg, by H. G. Wells (1897)
- The War of the Worlds, by H. G. Wells (1898)
- In The Crystal Egg, a Martian valley is described with several native fauna and flora, including "dense red weeds" growing alongside a water body. This reference, along with numerous others, seems to establish this and The War of the Worlds as taking place in the same universe.