A member of Lecanora hybocarpa aggregate. Material referred to the American species Lecanora hybocarpa has now been shown not to belong to this species but to include three cryptic species in Britain: Lecanora sinuosa, L. cryptosinuosa and L. subsinuosa (Arup et al, 2025). The contorted morphs that were called Lecanora sinuosa are also shown to be extreme forms of Lecanora sinuosa or L. subsinuosa. The cryptic species have some slight morphological differences, but can only reliably be told apart by DNA analysis. Arup et al (2025) recommended that morphological identified material is called Lecanora hybocarpa s. lat. for the time being.
Lecanora sinuosa is very similar to L. cryptosinuosa and L. subsinuosa. Arup et al (2025) found only minor differences from L. subsinuosa, which are not entirely constant between populations. Lecanora sinuosa has paler discs than those in L. subsinuosa which are often medium to ±dark or greyish brown. Additionally, the disc pigmentation in L. subsinuosa is often not uniform and shades of brown vary within a single apothecium. Young apothecia in L. subsinuosa are sometimes very thinly pruinose and their margin is often dentate in the inner edge. Macroscopically, the thalline margin is thicker in L. sinuosa (50–300 μm) compared to 50–150(–300) μm thick in L. subsinuosa. Finally, the apothecial cortex in L. sinuosa is usually somewhat thinner (12–25 μm) than in L. subsinuosa (20–50(–60) μm). Nevertheless, for accurate identification, a DNA barcode is recommended and, in the case of L. cryptosinuosa, even necessary.
The species grows on various deciduous trees in open landscape and light forests (Arup et al, 2025).
It is widely distributed across the Mediterranean and Atlantic parts of Europe. In Britain, Arup et al (2025) confirmed it from one location in Scotland: on an Ash twig in a stream valley close to the coast in old-growth forest, Old Poltalloch, Kilmartin, Argyll. However, from the minor differences with L. subsinuosa given by Arup et al (2025), it seems that L. sinuosa is likely to form a significant proportion of the Lecanora hybocarpa s. lat. population in Britain, even if it is not possible to assign individual specimens to the species with confidence. This should be confirmed by sequencing. [NB The current dot map includes extreme contorted morphs of both Lecanora sinuosa and L. subsinuosa]
From the distribution, habitat and abundance across Europe (Arup et al, 2025) this cryptic species is likely to be a common species in Britain and of Least Concern.
Arup, U., Malíček, J., Schiefelbein, U. & Holien, H. (2025) Lecanora hybocarpa and similar European species. The Lichenologist 57:239-255. doi:10.1017/S0024282925101291
Text by Neil A Sanderson based on Arup et al (2025).