Please bear with me, there’s a lot going on with the naming on the slide, which I will discuss in a minute. Labelled as Navicula speciosa, from Climacum Valley, USA. Prepared by JA long. Single example along with a Pinnularia sp. Some ‘bubble’ like features in the mountant, visible on the low magnification image. Olympus BHB microscope using 450nm LED light. 63x Leitz Pl Apo 1.4 objective, oil immersion. Olympus Aplanat Achromat condenser, oil immersion, oblique lighting. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850. 10 images stacked Zerene (Pmax).
Right, what’s going on here? First the location. The slide says Climacum Valley, USA. I hunted for Climacum Valley online and eventually found a reference which mentioned it as Climacum Creek, Washington, maybe near the mouth of Port Washington, but I couldn’t find it on a map. I did however find a Chimacum Creek in Washington. Chimacum Creek empties in Port Townsend Bay (a known location for diatoms), just north of Irondale. So for now I am assuming this should be Chimacum not Climacum and that is in the state of Washington.
Second the name. The slide says Navicula speciosa. N. speciosa does appear in Schmidt’s Atlas on Plate 295, Figs 8,9. It looks identical to these. Yay, I thought. In Schmidt’s it says “Navicula speciosa, nov. spec. Jacoma, Washington.”. I am assuming for Jacoma it should read Tacoma, as again, I couldn’t find a Jacoma, Washington, and J looks like T sometimes when handwritten. In Schmidt though it is also referred to as Navicula pseudoschummaniana nov. nom. in the text for Plate 309. On the slide label, below Navicula speciosa there is something written in pencil, and knowing what I know now, this looks to be ‘pseudoschumanniana‘. On the ANSP site, on the card for N. speciosa, it says “Hustedt remained this taxon: Navicula schumanniana Hustedt in Schmidt’s Atlas t. 309 (1914) (because of Navicula speciosa Mann 1907). When transferred to Caloneis it must be cited as per Simonsen (Caloneis schumanniana (Hust.) Simonsen)”. Caloneis schumanniana is referred to in: Cleve, P.T. (1894). Synopsis of the naviculoid diatoms. Part I. Kongliga Svenska Vetenskapsakademiens Handlingar Series 4 26(2): 1-194, 5 pls. (p.53). In this there is a good description – shown above – and it looks like it would fall under the variation of Caloneis schumanniana var. biconstricta based on the information in there. According to AlgaeBase this name is currently regarded as a synonym of Caloneis limosa (Kützing) R.M.Patrick. On the Diatoms of North America website I got another lead though as it shows Caloneis lewisii, which looks pretty much identical to the one on this slide (see the page here), and mentions that Krammer and Lange-Bertalot (1986) illustrate a very broad concept of C. schumanniana (Grunow) Cleve which includes C. lewisii. For the US flora, the shape and size series of C. lewisii is treated as distinct at the species level. So, at the end of all this, this ‘Navicula speciosa‘ diatom looks to be currently referred to as Caloneis lewisii….. Phew, got there in the end (hopefully).