In the post I wrote just after John Lund’s death had been announced (see: “John Walter Guerrier Lund (1912-2015)”), I mentioned that there was a diatom genus named after his house in Ambleside. As I was in the area, I thought I would pay a quick visit so that I could put a picture of Ellerbeck, the house, alongside images of Ellerbeckia, the genus. I walked down off Loughrigg Fell, through Ambleside and onto the road that leads out towards Kirkstone Pass. A left turn onto, Sweden Bridge Lane followed by a right onto Ellerigg Road brought me, a couple of minutes later, to Ellerbeck, the last of a row of stone cottages right at the edge of the village.
Set on a hillside and surrounded by garden plants, Ellerbeck was not an easy house to photograph, so forgive the odd perspective in the picture below. The gardens around Ellerbeck are, I imagine, quite wonderful in the summer, though today was not a day to linger.
Ellerbeck: the home of John and Hilda Canter-Lund in Ambleside, Cumbria, photographed May 2015.
The next pictures show Ellerbeckia arenaria, the only representative of the genus found in the UK. First there is a colony of live cells; after this, I have included some views of cleaned valves. It is, as you can see, a large, heavily silicified valve with a distinctive cross-hatched pattern on the mantle. The cells are joined together to form long chains, which often stay together even after the cells have been cleaned with oxidising agents. One interesting feature of Ellerbeckia that is not easy to see with the photographs here is that the two valves that make up the cell wall are different from one another. One has a convex face, whilst the other has a concave face. The radial markings on the valve face also differ, so that the “ridges” on one knit with the “grooves” on the next. This may explain why the colonies are so resilient compared to, for example, Melosira varians (see “Fertile speculations”).
Ellerbeckia arenaria, photographed by Chris Carter.
There is an irony to Ellerbeckia, the genus, being named after a house surrounded by the soft waters of the Lake District in northern England. Looking at my database, I noticed that most of my records were from hard waters in the south, including several chalk streams. I have found it in Cassop Pond, near my house, which is at the foot of the Permian limestone escarpment, but I would not expect to find it in the softer waters of the Lake District. On the other hand, my old copy of West and Fritsch (1927) says it “occurs on wet rocks, sometimes forming crisp mat-like masses on dripping sandstone, and is common on the Brit[ish] Carboniferous sandstone.” Maybe I’m just not looking in the right places.
Cleaned valves of Ellerbeckia arenaria, from the Great Stour (Kent), Ripper’s Cross, May 2011.
Crawford, R.M. (1988) A reconsideration of Melosira arenaria and M. teres, resulting in a proposed new genus. pp. 413-433. In: Algae and the Aquatic Environment, edited by F.E. Round. Biopress, Bristol.
West, G.S. & Fritsch, F.E. (1927). A Treatise on the British Freshwater Algae. Cambridge University Press, Cambridge.