Evolutionary history of plants phloem on the outside. Since xylem cells comprise dead, lignified tissue, subsequent rings of xylem are added to those already present, forming wood. The first plants to develop secondary growth and a woody habit, were apparently the ferns, and as early as the Middle Devonian one species, "Wattieza", had already reached heights of 8 m and a tree-like habit. Other clades did not take long to develop a tree-like stature. The Late Devonian "Archaeopteris", a precursor to gymnosperms which evolved from the trimerophytes, reached 30 m in height. The progymnosperms were the first plants to develop true wood, grown from
Seeds of Destruction corn. He shoots Doc Cooper and is about to kill Linda when her husband, Rex, knocks Harold out. The episode ends with a shot of Rex and Linda holding each other while workers in haz-mat suits use flamethrowers to burn the corn and milkweed plants. Seeds of Destruction "Seeds of Destruction" is an episode from the sixth season of "The Outer Limits". It originally aired on 3 March 2000. A veterinarian in a small farming town probes links between the rash of fast-growing tumors and a new breed of genetically engineered corn. "Macroseed", a cutting edge biotechnology company, chooses the