Common orange lichen

Description:

Foliose lichen. Two different specimens spotted on the same tree, one on the sunny side (south-the yellow one) and the other on the wet side (north-the green one). The colour change from yellow to green as the humidity increases. The vegetative body of the lichen, the thallus, is foliose, and typically less than 8 centimetres wide. The lobes of the thallus are 1–4 mm in diameter, and flattened down. The upper surface is some shade of yellow, orange, or greenish yellow, while the lower surface is white, with a cortex, and with sparse pale rhizines or hapters. The vegetative reproductive structures soredia and isidia are absent in this species, however, apothecia are usually present.

Habitat:

Spotted on a Holm oak tree at Parque Nacional de Monfragüe