The characteristic that unites the Filicales as a monophyletic clade is the presence of leptosporangia with an annulus-an area of specialized cells involved in dehiscence. […] Leptosporangia typically produce only a few spores, and are most commonly homosporous.

A decisive argument supporting this hypothesis was the discovery of a remarkable characteristic of the arrangement of the Uranian rings: near the outer edge of the rings there exist several orbits each of which is in resonance with a pair of rings simultaneously.

I guess I have no choice, she sighed.

She was very mature for a sophomore and had several friends who were juniors or even seniors.