Many Little Feet


Common or rock polypody, American wall fern, rockcap fern
Polypodium virginianum

a small stand on the Cabin John trail


This little fern is no less charming for being incredibly common.  It’s found throughout most of the eastern US and Canada except for parts of the deep south.  Although short (the fronds are usually about twelve inches long), the rhizomes will form massive colonies in suitable habitat, which consists of all sorts of rock outcroppings and rocky soils in moist shade.



an itty-bitty specimen at Carderock; it doesn’t have much soil to grow in!


It’s also an easy fern to identify, especially at this time of year, since it’s evergreen.


new fronds in late April along the Cabin John trail

What’s Green Now? Rock Polypody


Polypodium virginianum; Polypodiaceae

There are a few native ferns that are evergreen: ebony spleenwort, some of the woodferns (Dryopteris species), Christmas fern (in milder winters).  I’ve seen a few around but haven’t been able to identify them.  Rock polypody is pretty easy, though.  I love how it grows right out of stone, needing very little soil. Being a fern, of course, it won’t flower, but here’s how it looks in mid July:


There are vast stands of it on the rocky bluffs around Carderock.