Simplify the following text for a Grade 12 native English-speaking person.
Original: A primitive Silurian land plant with xylem and phloem but no differentiation in root , stem or leaf , was much-branched Psilophyton , reproducing by spores and breathing through stomata on every surface , and probably photosynthesizing in every tissue exposed to light .
Simplified: A primitive Silurian land plant with xylem and phloem but no differentiation in root , stem or leaf , was much-branched Psilophyton . This plant reproducied by spores and respired through stomata on every surface , and probably photosynthesizing in every tissue exposed to light .