Pioneer Valley Fern Society

Bracken Ferns

More Interesting than you may think!

While we are often out looking for the unusual or rare ferns, we overlook some interesting and lovely common ones. Such is the case with our Northern Bracken Fern (Pteridium aquilinum). Most people probably recognize this common roadside fern and tend to ignore it (as I did). Last year I started seeing postings in our area for Bracken Ferns on a botanical website which showed unusual characteristics for some Bracken within our region, and even sometimes a slightly different name!

The photo attached to this article shows a closeup of a Bracken fern I just saw in Petersham this week. There are two definitely different features. The first is that it is a fertile frond, with the sori hidden under the rolled leaf margin. These rolled margins start white and then turn brown with time. Finding a fertile Bracken fern frond was etremely unusual until this year! Maybe it is all the rain, but we have seen many patches of fertile bracken this year.

The second major difference with this Bracken fern is the shape of the pinnules or subleaflets. Normally they are not this divided, but are rather like the ends of the pinnules in this photo. I think it makes them much more attractive than normal Bracken ferns. Sometimes this alternate subleaflet shape, in combination with a few other characteristics, is used to identifly what some people are calling "Eagle Fern" (Pteridium aquilinum latiusculum). We are not sure whether to go with this new labeling or not, but we are seeing a lot of Bracken ferns with at least some of these more divided pinnules, and fertile too. So for now, it is worth at least being on the lookout for the fertile fronds of Bracken, and sometimes the unusual form of the pinnules too.

In case you are interested, we are holding a workshop through Native Plant Trust this Saturday at the Mt Toby Waterfall. Registration is through the Native Plant Trust. The Calendar listing has more details. We are working on our September schedule and should have some additional events on there soon.

Happy Ferning!