A macrolichen that is recognizeable also to non-specialists.
Thallus saxicolous, opaque, pale green-grey, up to I cm high, forming dense. compacted, irregularly spreading colonies without a distinct.
delimited holdfast. Laciniae fragile. simple or sparingly branched, up to I mm broad. fistulose, at first more or less terete, but soon flattening as
the lower tissue layers split open almost to the base. exposing the medulla. Apices often revo-
lute. Soredia absent. Cortex indistinct, chondroid tissue of uneven thickness, medulla dense. Apothecia and pycnidia not seen. TLC: divaricatic acid & usnic acid (+/-).
See Aptroot & Schumm (2008) for a key to distinguish this and similar species.
This macrolichen belongs to a genus with (for fungi) surprisingly many species with narrow distributions. This species is only known from two volcanoes on the small island of Porto Santo.
Described in 1980 and never found anywhere else, but always observed by lichenologists visiting the type locality.
Global assessment is same as European assessment:
Criterion A: does not apply.
Criterion B: does not apply.
Criterion C: does not apply.
Criterion D: estimated <250 individuals overall occurring based on definition of 1 individual = 1 m2 (see Guideline drafts for fungal red-listing 20140415), fulfilling criteria of D1; AOO is <20 km2 and number of locations is 1. Fulfills criteria of D2 for VU.
Criterion E: does not apply.
The species is proposed for listing as EN D1.
Only on the small island of Porto Santo, and there only on two volcanoes, viz. Pico de Facho and terra Chã.
Growing together with other endemic macrolichens, such as Anzia centrifuga, Ramalina erosa, R. jamesii, R. nematodes and R. timdaliana.
Only on the rock of the summit on two volcanoes, Area of Occupancy probably less than a square decameter. About 200 specimens were seen during an assessment in May 2015 (Aptroot, pers. comm.), but only 10% of the suitable habitat on Porto Santo could be investigated (much of it is on steep cliffs).
Population Trend: Stable
On exposed lava rock at the summit of an old cone at 515 m altitude, and at a another lava cone facing the sea at 375 m altitude.
Direct: Increased climbing of the summit by tourists will deteriorate the populations.
Direct: Further collecting by lichenologists or naturalists, which should be forbidden.
Indirect: Climate change may change this unique habitat, and even with subtle changes the chances are high that the species goes extinct soon. It will in any case not be able to successfully colonize another locality, not on its own, and possible also not with human help, as the conditions are apparently critical. Why else would this species be restricted to such a small area in the world?
Tourism to the summit of the Pico de Facho should be strictly regulated, either by forbading access altogether (which will impossible to control) or rather by opening a small trail and putting an information shield in place alerting the tourist on the unique lichens present, and the harm done to them by trampling.
The known locality at Terra-Chã is along a trail and is susceptible to accidental removing. However, the existence of further localities, in places that are difficult to reach, is likely.
The species should feature on a leaflet with protected plants.
Krog, H. and Oesthagen, H. 1980 Two new Ramalina species from Porto Santo, the Madeira Islands. Norwegian journal of Botany 27: 185-188.
Aptroot, A. and Schumm, F. 2008 Key to Ramalina species known from Atlantic islands, with two new species from the Azores. Sauteria 15: 21-57.
Sérusiaux, E. 1989 Liste Rouge des macrolichen dans la Communauté Europeenne. Département de Botanique, Liège.