''Punctelia missouriensis'', commonly known as the mealy speckled shield lichen, is a species of foliose lichen in the family Parmeliaceae. It is found in the southeastern United States, where it grows on tree bark and on rocks.

Taxonomy

It was formally described as a new species in 1992 by Gerould Wilhelm and Douglas Ladd. The type specimen was collected by the authors in Crawford County, Missouri, in

Onondaga Cave State Park Onondaga Cave State Park is a Missouri state park located on the Meramec River approximately southeast of the village of Leasburg, Missouri, Leasburg. The park was established in 1982. Park activities include cave tours, camping, fishing, hikin ...

. The specimen was found growing on a '' Juniperus virginiana'' in the Vilander Bluff Natural Area. Mónica Adler interpreted the soredia of this species as tiny isidia, and proposed to synonymise the taxon with the South American species '' Punctelia punctata'', but other authorities considered it to have sufficient morphological differences to warrant distinction as an independent species. It is colloquially known as the mealy speckled shield lichen.

Habitat and distribution

''Punctelia missouriensis'' is found in the southeastern United States. It occurs in the tallgrass prairie biome in the

U.S. Interior Highlands The U.S. Interior Highlands is a mountainous region in the Central United States spanning northern and western Arkansas, southern Missouri, eastern Oklahoma, and extreme southeastern Kansas. The name is designated by the United States Geologica ...

. Here it occurs regularly on the trunks of oak trees in open prairie and open savanna. It also occurs on

siliceous rock Siliceous rocks are sedimentary rocks that have silica (SiO2) as the principal constituent. The most common siliceous rock is chert; other types include diatomite. They commonly form from silica-secreting organisms such as radiolarians, diatoms, or ...

faces with partial shade. Although it was reported to occur in South America, the specimens that were analyzed were actually of ''Punctelia punctata''.

References

{{Taxonbar, from=Q10646752 missouriensis Lichen species Lichens described in 1992 Fungi of the United States Fungi without expected TNC conservation status