Naked (Psilophyton)

1
genus of
Psilophytaceae
), a representative of the naked fernssee naked ferns (fossils)
)
. The plant body is a branch axis system, and the roots and leaves have not differentiated. Appeared in North America and Europe early mud basin world to late mud basin world early.Stems are false single-axis branching, side branches diagonal fork, smooth or prickly, the outer cortical layer is very thick, with thick corners
organic
, the middle column is a solid native medium column, the wood part is the heart-starting, the tube cells have secondary thickening, located in the middle of the thread thickening, the peritone thickening of the mesh. The skin has pores, but the thorns are not seen. Spore sacs are oval in length, with handles, and are born in pairs at the top of the reproductive branch. The number of spore sacs varies from species to species,
up to
64. The front end tends to sag after the side branches have produced spore sacs. When the spore sac matures, it splits along both sides. A variant of the naked fern spore sac has been built in another genus called
Sawdonia
.and the former naked plant outline may have originated from the naked ferns.