Fernology and Ladybirds

Fernology and Ladybirds

Today, I touched up on my fern ID and spotted a new ladybird

In a lovely steep-sided glen near Fathom Mountain, I was having a look at the mosses and ferns which are abundant in the ravine. Everytime I take my fern book out I usually end up not using it, being preoccupied with trees and mosses (especially as of late). But today I sat down near the plunge pool within the woodland and studied a fern.

I thought it would we good to highlight the process I went through in order to get to an ID. For clarification, I use James Merryweather’s Ferns of Britain ID guide which is pretty detailed but not overwhelming.

First, I worked out what group of ferns it belongs to. I deduced it was a type of male-fern within the genus Dryopteris. Male-ferns are a difficult group to master since ferns as a whole show considerable variation influenced by hybridisation and environmental conditions like dense shade.

Secondly, I looked carefully at the junction where the pinnule connects to the main stem called the rachis. For this specimen, it was dark on both the underside and dorsal side of the fern. This narrows it down to three possible species and rules out the very common and widespread Dryopteris felix-max.

Next in the process I looked at the shape of the pinnules (this is where things get messy for this specimen). The pinnules were blunt-tipped with several short apical teeth. Certain species in this group have more acute-tipped pinnules and/or very few teeth. At this point I am leaning towards two species.

Then, I used a feature which is not diagnostic but can be useful. Looking at the very first pinnule where it connects to the rachis was detached from the rachis. At this point it’s a toss between D. borreri and D. cambrensis. To separate them we can discriminate between the length of the first pair of pinnules compared to the adjacent pair. Im D. borreri the first pair is not noticeably longer, whereas, D. cambrensis are noticeably longer. This specimen aligned with the former classification.

At this time of year, there are no fertile parts on the underside of the plant which are useful features to have when IDing this group. Plus, during Winter, ferns can be half-eaten, browning and dying back which can throw off an accurate ID.

My final conclusion is that it is D. borreri. I am no expert on ferns, and don’t take this as gospel, this is just illustrating the process that I go through when trying to come to an ID.

In other news, while I was looking at ferns I spotted a lovely Orange Ladybird (Halyzia sedecimguttata) which is a first for me and a new location for the bug, the closest being Sliabh gCuillinn. It is relieving when after struggling with difficult groups that you find an organism with an unequivocal identification.

Image: orange ladybird on underside of said fern. Note the dark marks on the base of each arm.