Guyanagaster lucianii is a rare, distinct fungus endemic to the Guiana Shield region of northern South America where it is known from four collections at a single location in Guyana. It is possibly a root parasite of Dicymbe altsonii and Eperua falcata. Only a tiny fraction of its possible suitable habitat has been surveyed. Potential host plants occur in a large region encompassing parts of Venezuela, northern Brazil and southeast Colombia. This entire region is very under-sampled, being very remote and completely unsurveyed. In total approximately 0.002% of its potential suitable habitat has been surveyed for fungi. It is not possible to estimate population size or trends, EOO, or AOO. Increasing threats from timber and mineral extraction, and land use changes are anticipated, with the potential for these to be rapid if further road construction occurs. It is therefore assessed as Data Deficient, and further survey work in this region is urgently needed.
This is one of two members within Guyanagaster which is the sister genus to Armillaria; phylogenetic placement and relatedness may change with increased survey and genetic barcoding data.
Guyanagaster lucianii is a rare species endemic to the Guiana Shield region of northern South America where it has only been found as a saprobe on Eperua spp. trees. Furthermore, Guyanagaster lucianii is a close relative of the globally distributed Armillaria genus, which is a highly aggressive plant pathogen. This species should be considered due to its rarity, its narrow geographic endemism, and its importance in understanding the evolutionary history and spread of a highly important plant pathogen.
The species is currently known from one site in Guyana: Region 10 Upper Demerara-Berbice—Mabura Hill, elevation 161 m: 5.17, -58.70. Its full distribution is very uncertain.
The species is known from four collections made in 2011 & 2013 in June (1 collection) and December (3 collections) consisting of 1-9 basidiomata. A total of 18 basidiomata are known, representing four genets.
Population Trend: Uncertain
Its ecology is restricted to decaying roots of woody plants:
“Attached to decaying woody roots of Dicymbe altsonii and Eperua falcata in tropical rainforests. Known only from the type locality in the Mabura Ecological Reserve of Guyana.” (Koch et al. 2017).
“Ecologically, G. lucianii appears to occupy the same niche as G. necrorhizus. Basidiomata are hypogeous to subhypogeous and growing from the roots of dead and decaying trees. Both Guyanagaster species are white rotters as the decaying roots to which they are attached are all light-coloured, spongy and sometimes gelatinous.”.
The only currently known site for this species is from a region of Guyana with more habitat degradation and disturbance than most of the generally inaccessible interior. Current threats include logging, forest clearing and small-scale mineral extraction that can cause habitat disturbance and water pollution. Future threats from land-use changes and climate change are anticipated.
No conservation actions are currently in place for this species. Protection of habitat is needed.
Additional survey work to document the species’ distribution and abundance, taxonomy, and life history are needed.
“The known habitat for Guyangaster necrorhizus and G. lucianii are separated by only 125 km, so elucidation of their dispersal strategy is needed to understand the evolutionary forces that led to their speciation.” (Koch et al. 2017).
There is no known use or trade of this species.
Guyanagaster lucianii R.A. Koch & Aime, in Koch, Wilson, Séné, Henkel & Aime, BMC Evol. Biol. 17(no. 33): 12 (2017)
Index Fungorum Registration Identifier 815807