Evolutionary history of plants foliage consisted of fern-like fronds, although they were not closely related to ferns. The oldest fossil evidence of seed plants is of Late Devonian age, and they appear to have evolved out of an earlier group known as the progymnosperms. These early seed plants ranged from trees to small, rambling shrubs; like most early progymnosperms, they were woody plants with fern-like foliage. They all bore ovules, but no cones, fruit or similar. While it is difficult to track the early evolution of seeds, the lineage of the seed ferns may be traced from the simple trimerophytes through homosporous Aneurophytes. This
The Secret Life of Plants plants "might originate in a supramaterial world of cosmic beings which, as fairies, elves, gnomes, sylphs, and a host of other creatures, were a matter of direct vision and experience to clairvoyants among the Celts and other sensitives." The book has been criticized by botanists such as Arthur Galston for endorsing pseudoscientific claims. According to Galston and physiologist Clifford L. Slayman many of the claims in the book are false or unsupported by independent verification and replicable studies. Botanist Leslie Audus noted that the book is filled with nonsensical "outrageous" claims and should be regarded as fiction. The book was