Plant of the Week
Pimpled kidney lichen (Nephroma resupinatum (L.) Ach.)
By Chantelle DeLay
Nephroma resupinatum is a lichen in the family Nephromataceae, Kingdom: Fungi. In North America, Nephroma resupinatum is found in the Upper Midwest and north of the United States and Canada border along the Great Lakes and east to the Atlantic Coast. This species also occurs in northern California, coastal Oregon, Washington, and extends into British Columbia.
This species is a foliose (leaf-like) lichen that grows on mossy rocks and trees in humid climates. Nephroma resupinatum is a grayish-brown, fuzzy lichen with apothecia on the undersides of the lobe tips and several, smaller lobes (called lobules) on the edge of the lobes. The underside of this species is fuzzy, light in color and has pale bumps in the fuzz. In all Nephroma species, the apothecia (spore-producing reproductive structures) occur on the underside of the lobes. Specimens average approximately 10 cm in diameter, with lobes that are around 1 cm wide. This species has two methods of reproducing: fragmentation – parts of the lichen body break off and colonize elsewhere, developing a new lichen structure; and spores,which are released by the apothecia.
N. resupinatum is normally found in forests that are humid. This lichen is most common in areas of maritime influence, such as the Pacific Northwest or the Great Lakes region. N. resupinatum is extremely sensitive to air pollution. Air pollution affects many lichens, overwhelming their thalli with toxic chemicals and blocking their normal metabolic functions.