This taxon has long been recognized as distinct, although under different names. Imshaug & Brodo (1966) recognized it as a subspecies of Lecanora caesiorubella, using the name L. caesiorubella subsp. prolifera. Lumbsch et al. (1997) then recognized it as a species due to its unique chemistry and use the name Lecanora subpallens. That name was widely used until Brodo et al. (2019) recognized that there was an older name available (L. protervula). Regardless of the name, the taxon was been recognized as distinct, and treated in multiple taxonomic works, for well over half a century.
Why suggested for a Global Red List Assessment?
This species is widespread in temperate and subtropical eastern North America, where it is endemic (Imshaug & Brodo 1966).
Population and Trends
Comprehensive detailed population data are unavailable for this taxon. However, it is suspected to be stable given that it is common and widespread in many different habitats and is tolerant of disturbance (Brodo 1968, Lendemer & Noell 2018, Tripp & Lendemer 2020). There is no indication the species is restricted to a narrow range of habitats or substrates.
ASSESSMENT: Least Concern
Given the large number sites where it is extant, large geographic range, large population size, and absence of documented or suspected declines, the species does not meet the thresholds for any threat criteria.
Population Trend: Stable
Habitat and Ecology
Lecanora protervula is common and widespread in forested habitats at middle to low elevations where it occurs primarily on the bark and branches of hardwood trees and shrubs (see Imshaug & Brodo 1966, Lendemer & Noell 2018, Tripp & Lendemer 2020).
The primarily threat to this species is urbanization as it does not typically occur in densely urban areas. Otherwise it appears to be tolerant of disturbance (Lendemer & Noell 2018).
Housing & urban areasCommercial & industrial areas
Many sites where this species occurs are included in protected areas and thus the species is incidentally protected there. It would benefit from broader awareness and training as to the impacts of urbanization on lichens.