When Tucanopollis was known only as dispersed pollen, Doyle and Hotton (1991) suggested that it represented relatives of Clavatipollenites and Chloranthaceae that were either more primitive or more derived in having a continuous tectum, but they also recognized its similarities to Saururaceae. Friis et al.
(2011), this correlation probably also holds in Canrightia (which had small, simple bisexual flowers comparable to those of insect-pollinated Saururaceae, Piperaceae, and Chloranthus) and in Chloranthistemon (Crane et al., 1989).
Kaul, "Saururaceae," in Flora of the Great Plains, R.
Calderon, Saururaceae. Flora del Bajio y Regiones Adyacentes, vol.
The angiosperms closest to the origin of monocots include Chloranthaceae and the Piperales (Aristolochiaceae, Lactoridaceae, Piperaceae, and Saururaceae), all of which do have vessels.
Saururaceae, the marsh-inhabiting close relatives of Chloranthaeeae, have nearly lost cambial activity in stems, but they have not lost metaxylem vessels.
Phylogeny of Saururaceae
based on morphology and five regions from three genomes.
. They are always neglected in Tertiary palynological studies
4) and the species studied in Piperaceae and Saururaceae
contain S-type sieve-element plastids; most species of Aristolochiaceae, P-type.
Inflorescence and floral development in Houttuynia cordata (Saururaceae
Furthermore, in all three topologies the scalariform perforation plates found in some members of Saururaceae are most parsimoniously interpreted as derived relative to simple perforation plates, which are shared by the remaining members of Saururaceae and other paleoherb families (Piperaceae, Aristolochiaceae, Lactoridaceae).
Within the "paleoherb" families, the Saururaceae and Aristolochiaceae are polymorphic for this character, and the phylogenetic context provided by these cladograms implies that the distinctly bordered pits in some Saururaceae and Aristolochiaceae represent reversals.