Closely related to the Antarctic endemic A. gwynnii C.W. Dodge & E.D. Rudolph, but morphologically and molecularly distinct.
Known from only two localities c. 7.5 km apart on the north shore of Saunders Island (Falkland Islands).
Known from only two locations c. 7.5 km apart on the north shore of Saunders Island. (AOO = 8 km2, EOO= 8km2).
Known from only two localities c. 7.5 km apart on the north shore of Saunders Island. First collected and identified as A. gwynnii by R. L. Lewis Smith in 2000. Discovered at a second site 7.5 km to the east by Fryday in 2015 (Fryday et al. 2019) and shown to be a distinct species by Øvstedal et al. (2018) based on molecular investigation of these collections.
On low, siliceous rocks, loosely associated with rockhopper penguin rookeries. In 2015 it was seen only in the immediate vicinity of the rockhopper rookery (-51.308°, -60.12°) and the 0.5 km to the east - becoming less frequent and less well-developed further east. It was not seen at all further east along the coast as far as rookery cottage (-51.306°, -60.10°). The extension to the east of the penguin rookery being a consequence of the prevailing strong westerly winds that are a near constant feature of the islands.
Both penguin rookeries are subject to organized tourist excursions -especially the colony at “The Neck”. However, this is unlikely to be a major threat because of the remoteness of the localities
Other suitable habitats on Saunders and neighbouring islands, should be surveyed for further colonies of this species. This would ascertain if the hypothesis that it is associated with penguin rookeries is correct and also give a better idea of the extent and distribution of the species.
Acarospora malouina has not been discovered elsewhere among the c 5,000 collections from the Falkland Islands nor in the c. 10,000 lichen collections from southern South America held in the herbarium of Michigan State University herbarium (MSC) so is evidently extremely rare. It is probably confined to the northern shores of the northernmost islands of the archipelago.
Øvstedal, D.O., Lindblom, L., Knudsen, K. & Fryday, A.M. 2018: A new species of Acarospora from the Falkland Islands (Islas Malvinas). Phytotaxa 340 (1): 86–92.
Fryday, A.M., Orange, A., Ahti, T., Øvstedal, D.O. & Crabtree, D.E. 2019: Checklist of lichenized and lichenicolous fungi reported from the Falkland Islands. Glalia 8(1): 1–100.