Division: Pteridophyta (Filicophyta)
The class Osmundopsida contains the sole order Osmundales, which contains the sole family Osmundaceae.
All the Osmundoids have chromosome counts based on n=22. In fact, it has been one of the most stable groups with regard to chromosome counts, especially considering its known antiquity. The n=22 is clearly a tetraploidy from n=11, the stem number for vascular plants.
Order of Osmundopsida:
This page was last revised on 11-10-1997.