Eupolypods I
Encyclopedia
Eupolypods I is a clade
of ferns in the order Polypodiales
. It probably diverged from Eupolypods II during the mid-Cretaceous. The divergence is supported by both molecular data and an often over-looked morphological characteristic which lies in the vasculature of the petiole. Most species that make up the Eupolypods I clade have three vascular bundles. The only exceptions are the Grammitid ferns which have one, and the genus Hypodematium
which has two. This differs from Eupolypods II which mostly have two vascular bundles (except the well-nested blechnoid ferns which generally have at least three).
Clade
A clade is a group consisting of a species and all its descendants. In the terms of biological systematics, a clade is a single "branch" on the "tree of life". The idea that such a "natural group" of organisms should be grouped together and given a taxonomic name is central to biological...
of ferns in the order Polypodiales
Polypodiales
The order Polypodiales encompasses the major lineages of polypod ferns, which comprise more than 80% of today's fern species. They are found in many parts of the world including tropical, semitropical and temperate areas...
. It probably diverged from Eupolypods II during the mid-Cretaceous. The divergence is supported by both molecular data and an often over-looked morphological characteristic which lies in the vasculature of the petiole. Most species that make up the Eupolypods I clade have three vascular bundles. The only exceptions are the Grammitid ferns which have one, and the genus Hypodematium
Hypodematium
-Species:*Hypodematium crenatum Kuhn*Hypodematium daochengense K. H. Shing*Hypodematium fordii Ching*Hypodematium glabrius Holtt.*Hypodematium glabrum Ching ex Shing*Hypodematium glandulosum Ching ex Shing...
which has two. This differs from Eupolypods II which mostly have two vascular bundles (except the well-nested blechnoid ferns which generally have at least three).