I was shown Fossombronia wondraczekii for the first time last year, and learnt that to identify these plants to species you need to look at the spores. Without a microscope that just can’t be done, and even now I have one I realise I’d been putting off looking because it sounded rather hard. It turns out it isn’t.
Rachel Bicker at Gatwick asked me to do an introductory bryophytes session recently, which was fun, and we finished off at a pond in the woods. It had a patch of New Zealand Pigmyweed (Crassula helmsii) but Rachel has had good success in considerably reducing it. On the ground was still marked out the area which had been covered in black plastic much to stop it growing. As it turned out, that was where we found the liverwort.
The most abundant bryophyte there was the moss Tortula truncata, copiously fruiting, but as we looked a bit more closely (and got increasingly muddy) we found the frilly, lettuce-like Fossombronia. Happily, there were lots of capsules, so I brought a piece home to let it mature and then check the spores.
The spore was about 55×35μ, and the grooves on it about 4μ apart. There are maybe 35 or 36 spines, though it isn’t easy to count them. Watson tells us what to look for:
[wondraczekii] has spores with more close-set lamellae than those of F. pusilla (about 4μ apart, as against 8μ in F. pusilla) and they project as 28-36 spines around the margin of each spore.
Since the lamellae in F. pusilla are more widely-spaced, there are fewer of them projecting out too; Watson gives the range of 16-26 spines for that species.
That all turns out to be pretty easy and unambiguous, so that makes this Fossombronia wondraczekii, not a rare plant in the south east, but not one you find everywhere. It occurs on damp acid soil, often in woods and on the edge of tracks, as well as on pond edges. It often grows with F. pusilla, so one should never assume all the plants in a given area are all the same. Indeed, there are two other closely-related, though rarer, species which should not be discounted, either.
Having found and identified it, my curiosity led me to its name. The genus Fossombronia is named after the Tuscan politician and statesman Vittorio Fossombroni (1754-1844), who also had interests in mathematics, hydraulics and other scientific subjects. The botanist who coined the genus name was Giuseppe Raddi (1770-1829), who created the name for what is the type species of the genus, Fossombronia angulosa.
Our plant was first described by the Bohemian doctor August Corda (1809-1849), who gave it the name Jungermannia wondraczekii, though I can’t track down who Wondraczek was, unfortunately. With all the various re-working of species names and classification, it eventually was placed in the genus Fossombronia. Corda himself died at sea, on return from a biological collecting tour of Texas.
 Watson, E. Vernon. British Mosses and Liverworts: An Introductory Work, with Full Descriptions and Figures of over 200 Species, and Keys for the Identification of All except the Very Rare Species. Cambridge: Cambridge UP, 1968. Print.
 Atherton, Ian, Sam D. S. Bosanquet, and Mark Lawley. “Fossombronia pusilla / foveolata / wondraczekii / caespitiformis.” Mosses and Liverworts of Britain and Ireland: A Field Guide. Middlewich: British Bryological Society, 2010. 228-29. Web. 3 Nov. 2015. <http://www.bbsfieldguide.org.uk/sites/default/files/pdfs/liverworts/Fossombronia_pusilla-foveolata-wondraczekii-caespitiformis.pdf>.
 “Vittorio Fossombroni.” Wikipedia. Wikimedia Foundation, n.d. Web. 03 Nov. 2015. <https://en.wikipedia.org/wiki/Vittorio_Fossombroni>; and Pazzagli, Carlo. “Fossombroni, Vittorio.” Treccani. N.p., n.d. Web. 03 Nov. 2015. <http://www.treccani.it/enciclopedia/vittorio-fossombroni_%28Dizionario-Biografico%29/>. From Dizionario Biografico degli Italiani – Volume 49 (1997).
 “August Carl Joseph Corda.” Wikipedia. Wikimedia Foundation, n.d. Web. 03 Nov. 2015. <https://en.wikipedia.org/wiki/August_Carl_Joseph_Corda>.