Ophioglossum pendulum is an interesting, pretty fern.  It “infests” the root masses of some large-growing aspleniums, platycerium, and other epiphytes.  It can be grown readily without a host.

The photo above shows the variation between a form with straight, narrow fronds, a broad type, and the most common, easiest form.  Other variations are becoming available, as this species volunteers in collections

Above, the straight, narrow type.

Below is the broad form, easily the most decorative.

Ophioglossum pendulum has volunteered a number of times in my greenhouse, and at least twice outside.  The ones I give the #7, with a letter, are somewhat different from each other.  The two currently offered, 7a and 7c seem to differ slightly in the width of the fronds, but I am becoming uncertain of this distinction.  They are superb plants, and seem to have a youthful vigor. Below is 7a on the left, 7c on the right.

Below is a photo of a volunteer Ophioglossum pendulum, about 30 ft. up in a Sabal Palm. We are sometimes very dry, and it is a real surprise to see this so far north.