Chemically unique in that it contains usnic acid and caloploicin, both of which are otherwise unknown in the genus. This, and morphological characters, suggest it occupies an isolated position in the genus.
Known form only two localities in South Africa and apparently occupies an isolated position in the genus.
This species is assessed as DD, because we do not know for sure even whether the pressure on the fijnbos biome is deletorious to the species per se. It does not seem to fit any of the criteria A-E for global Red Listing.
South Africa. Two localities, one in Northern Cape, the other in Western Cape Province (Kantvilas et al. 2003)
(1) Republic of South Africa: Northern Cape Province: Namaqualand, Quaggasfontein 478, about 20 km southern from the village of Soebatsfontein, 17°33’18.8’‘E, 30°13’25.1’‘S, 380 m a.s.l., 4.4.2001, in succulent Karoo vegetation, on soil among granites, L. Zedda 5415.
(2) Republic of South Africa: Western Cape Province: Namaqualand, Vanrhynsdorp, Gifberg, 18°46’42.2"E, 31°47’19.2"S, 526 m a.s.l., 23.11.2002, in fynbos vegetation, forming biological soil crusts among plane sandstones, L. Zedda 5849 (M 0038981).
Unknown. Last collected in 2002.
Luciana Zedda, pers. comm. 4 Febr 2014 (e-mail to A. Aptroot): Found locally abundant at only two sites, but I think it could be more frequent in Namaqualand. Even if locally abundant, the species is surely vulnerable.
Population Trend: Uncertain
Occurs on soil in sheltered microhabitats among granites, sandstones in either dwarf Succulent Karoo shrub vegetation or, at higher altitude, fynbos vegetation.
The semi-desert Namaqualand area (a unique biodiversity hot-spot) is threatened by land use, especially grazing, and global climate change. Siphula flavovirens strongly depends on fog to survive (as many other lichens there) and any changes in water avalaibility will be deleterious (Luciana Zedda, pers. comm. 4 Febr 2014. e-mail to A. Aptroot).
Survey of other suitable habitat to assess the size and extent of the species’ current population.
Also it is important to know if the species can survive disturbed fijnbos areas or not.
Kantvilas, G., Zedda, L. & Elix, J.A. 2003: A remarkable new species of Siphula (lichenized fungi) from South Africa. Herzogia 16: 21-25.