Live sphagnum is amazing looking. Almost alien, because they are living fossils. A recent scientific discovery shows that sphagnum is as much as 600 million years old. The oldest fossils of land plants are recently discovered fossils of sphagnum:
http://www.journals.uchicago.edu/doi/ab ... 086/686242
Sphagnum was likely one of the first land plants, and clearly the most successful of the first plants to crawl onto land. Why do so many plants grow so well in the dead remains of sphagnum (both long fiber sphagnum and peat)? Likely because other plants evolved to grow well in the dead remains of sphagnum that had piled up over the surface of the earth over millions of years.
Many carnivorous plants likely evolved into carnivores because live sphagnum is a nutrient black hole. Live sphagnum rapidly soaks up nutrients used by plants, fungi, and bacteria... and sphagnum quickly converts these nutrients into acid. In other words, sphagnum engages in a sort of chemical terraforming that transforms its environment into a nutrient poor, moist, and acidic place. For millions of years this prevented other lifeforms from growing in sphagnum’s environment, but eventually some plants evolved adaptations to allow them to remain healthy in such an environment by obtaining their nutrients by eating animals.