The Paleoherbs are a group of several plant orders and families including: Piperales (Chloranthaceae, Piperaceae, Saururaceae), Aristolochiaceae, Nymphaeales, and the Monocots.

The flowers in this group tend to be small, with a simple or absent perianth and few numbers of floral parts.

For more information, including some pictures of Paleoherbs, check out this site from UC Berkeley.

Donoghue and Doyle's (1989) study of morphology implicated this group of plants as the most primitive living angiosperms. Later (Doyle et al. 1994) they also used 18S sequence data that further lend evidence for this group.

Some have suggested that their results show a bias of primitive angiosperm morphology as well as using Gnetales as the outgroup of phylogenetic analyses.