Two square meters of rock colonized on each of the first two localities:
The Barn, along God’s Path, on basalt, altitude 475 m,
South of Little Stone Top, on basalt, altitude 375 m.
The extent of the other two localities is not reported:
Half Tree Hollow, between Cowpath and Fort Knoll, altitude 475-525 m
Boxwood Hill, just S of the top, altitude 425 m
Species known from a few individuals. The two known localities could be destroyed in half an hour each by work intended to improve walking tracks for tourists, like adding hand rails along the path. That this is not hypothetical is shown by the total detcruction of the type locality of the first Red Listed lichen Anzia centrifuga in a similar way.
The species is very different from any other known lichen. Its assessment to the genus Dolichocarpus (with only one other species, only known from Chile) is somewhat schematic; its classification may change with phylogenetic research (e.g. it may turn out to be the only fruticose Enterographa), but its identity as endemic species without close affinities will not be affected.
Why suggested for a Global Red List Assessment?
One of the rarest lichens on earth, known from two rock faces, occupying only a few square meters. With the much increased tourism on St Helena, there is a severe threat.
EOO 128 sq km
AOO 12-16 sq km
The entire population is restricted to Saint Helena. It is known from known from 4 localities. Even if all suitable rock faces on the island are occupied, the EOO could not exceed 84 km2 and the AOO could not exceed 108 km2. It is suspected that other rock faces on the island may also support colonies of this lichen within the altitudinal range of 375-525 m.
Population and Trends
In two localities, a total of 2 square meters of vertical rock are occupied.
Habitat and Ecology
overhanging volcanic rock (basalt)
Rocky Areas [e.g. inland cliffs, mountain peaks]
Tourism is increasing, necessitating rails along paths etc, which can destroy locations, just like the original and at that time only known population of the first lichen on the Red List, Anzia centrifuga, was destroyed to ameliorate the walking track for tourists on Porto Santo
Tourism & recreation areas
Awareness of the species with local authorities
Resource & habitat protection
Fieldwork may well yield a few more localities, but total area on earth is less than 100 square meter for certain