Cetraria aculeata

Cetraria aculeata, the spiny Iceland lichen, is a dark brown to black fruticose lichen in the family Parmeliaceae. First described by Schreber in 1771 as Lichen aculeatus, it was transferred through several genera before being placed in Cetraria. The thallus forms shrubby tufts up to 5 cm (2.0 in) tall and reproduces mainly by fragmentation rather than ascospores. The species has a wide, bipolar distribution, occurring from the maritime Antarctic to the high Arctic and, at intermediate latitudes, in montane, steppe, and coastal habitats. Phylogeographic evidence suggests it evolved in the Northern Hemisphere and spread southward during the Pleistocene. Its broad ecological range has been linked to variation in its green algal photobiont partners, and it also harbours characteristic communities of associated alphaproteobacteria. Although globally widespread, some isolated tropical mountain populations are considered at risk of local extinction....read more on Wikipedia.