In the field of plant science, the tallest weed plant is a really interesting one. The only weed plant taller than itself, the giant plant grows to as large as five feet, three inches tall. This plant was one of the first plants to be scientifically studied as a whole plant. It has long, narrow leaves which can grow up to five feet in length. The plant is an annual, but can be grown from seeds.
The plant can also be made into a more complicated form, where it can be grown into a small plant that can be dropped from a plane, which then grows to about three feet tall.