Bare-bottom Sunburst Lichen

Gallowayella weberi is a foliose lichen that forms small thalli up to 4 mm wide, which adhere to surfaces ranging from closely to somewhat loosely attached. The lobes of the thallus are flat, ranging from horizontal to slightly ascending, and measure between 0.3 and 0.5 mm in width. The tips of these lobes often curve inward, and the outermost parts of mature lobes are truncated or cut off squarely. The upper surface of Gallowayella weberi has a yellow to orange color and is smooth to the touch. Its lower surface contrasts with a white color. The cortex, or the outer layer of the lichen, is made of tightly packed cells and is colorless, except for the presence of external anthraquinone crystals, which are chemical compounds often found in lichens. The photobiont (photosynthetic partner) is a unicellular green alga from the genus Trebouxia. The medulla, which is the inner tissue beneath the cortex, has a net-like structure made of short cells. Rhizines, which are root-like structures helping the lichen to anchor to its substrate, are mostly present and are white in color, turning yellow when exposed. They can be either attached to the substrate or free. …

Gallowayella weberi can grow on diverse substrates including bark and rock, as well as on artificial ones such as concrete and tombstones. It is native to North America, and herbarium-based mapping indicates that it is widespread across the eastern and central United States, with its centre of distribution in the coastal plain of the southeastern United States. At the Delaware locality originally used to describe Xanthomendoza rosmarieae, the lichen was abundant on roadside plantings of Norway maple (Acer platanoides).

Tremella xanthomendozae is a lichenicolous fungus that infects Gallowayella weberi (it was named when its host was classified in genus Xanthomendoza).

== References ==