The long and unfinished journey to understanding the diversity of violaceous Inocybes in subsection Geophyllinae

• First mention of this group is from North America by Peck (1874) as Agaricus geophyllus var. lilacinus. Gillet (1875) soon formalised the new combination as Inocybe geophylla var. lilacina (incorrectly using lilacinus).
• Kauffman (1918) promoted the variety to a new species, I. lilacina, suggesting it did not grow with I. geophylla in Michigan (US), and the colour difference was morphologically distinct.
• Traditionally placed alongside I. geophylla in section Tardae and subsection Geophyllinae.
• The separation from I. geophylla has not been followed by every author, but the US name has now been broadly applied to collections from across the world.
• Matheny and Swenie (2018) construct a phylogeny of subsection Geophyllinae using regions of ITS, 28S, and rpb2, and confirm that I. lilacina is a complex, and clades separately to the I. geophylla complex.
• Within complex I. lilacina, there are two European lineages that do not clade with collections from other continents or each other. As I. lilacina is a North American name, they are labelled I. lilacina sensu Larsson I and II, presumably after the 2012 description in Funga Nordica. Note that I. lilacina sensu Larsson I, includes a collection from Scotland.
• The geographic separation of species in the complex is interesting, especially considering that I often find basidiomes from complex I. lilacina with those from complex I. geophylla in the UK, and this contrasts with Kauffman’s observation in North America.
• A new species, I. ionolepis (2020), has recently been described from the UK and the Netherlands. This is also placed in complex I. lilacina and is violaceous but has distinct scales on the pileus.
• Other new European taxa have also been proposed, but no name or morphological distinctions have been proposed for either of the two mysterious European species.

References:

Matheny, P. B., & Swenie, R. A. (2018). The Inocybe geophylla group in North America: a revision of the lilac species surrounding I. lilacina. Mycologia, 110(3), 618-634.
Cullington, P., & Larsson, E. (2020). Inocybe ionolepis in Crous et al. Fungal Planet description sheets: 1112-1181. Persoonia 45:251-409.

Posted on November 24, 2023 01:08 PM by shelbourne