[general_re]

Althoug it would definitely go higher than any weed before it, this "space weed" actually sounds pretty ordinary if you look it up.

...the most likely candidate would be "a less fussy plant", possibly the common weed arabidopsis.

"Arabidopsis thaliana is a common plant used for laboratory research. It is a member of the Brassicaceae, or Mustard family, along with broccoli and cauliflower. Arabidopsis is considered to be a "model" organism because it is easy to grow in the lab, it has a short life cycle and makes lots of seeds (which makes it good for genetics) and it has a small genome compared to other higher plants (like maize)."

Space broccoli. That sounds like a bad idea - carpet bombing the Martians with space broccoli.

[uglybiker]

How 'bout space kudzu? That stuff'll grow most anywhere!

[RightWhale]

Although Arabidopsis thaliana thrives even in Alaska it has to be replanted every year because moose eat all of it.