• Proposed
  • Under Assessment
  • Preliminary Assessed
  • ENAssessed
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Rickiella edulis (Speg.) Pfister

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Scientific name
Rickiella edulis
(Speg.) Pfister
Common names
IUCN Specialist Group
Cup-fungi, Truffles and Allies
Assessment status
Proposed by
E. Ricardo Drechsler-Santos
Adriana Calle, E. Ricardo Drechsler-Santos, Luis Funez, Thiago Kossmann, Kelmer Martins da Cunha, Donald Pfister, Gerardo Robledo, Pablo Sandoval-Leiva, Tatiana Sanjuan, Aída M. Vasco-Palacios
Gregory Mueller
Comments etc.
Anders Dahlberg, James Westrip
David Minter

Assessment Notes


Rickiella edulis has been recorded from 4 distinct localities: South Region of Brazil, in Araucaria Forest vegetation; Asunción, in Paraguay, and two large areas in Argentina: one in Salta, belonging to the Gran Chaco vegetation (Romero et al. 2012), and one in Misiones, belonging to Atlantic Forest vegetation (Vignale et al. 2015). There is only the one record from Paraguay, near Asunción, and that site likely is no longer extant. Within Brazil and Argentina it has rarely been collected even though the species is relatively large and distinctive, and there have been a number of mycological surveys within potential habitats. Thus, the species is considered rare throughout its range. Before deforestation, the species was likely broadly distributed but uncommon. Assuming that there were over 10,000 mature individuals in the past, land use changes over the last 100 years have decreased the population to less than 2,000 mature individuals. It is, therefore, listed as Endangered.

Taxonomic notes

Rickiella edulis was originally described by Spegazzini (1891) as Peziza edulis. Now this species belongs to the monotypic genus Rickiella (Pfister 1987). The species Rickiella transiens Sydow, described in 1904 (Sydow in Rick 1904) was considered a synonymy of R. edulis by Pfister (1987).

Why suggested for a Global Red List Assessment?

This is a very rare species, having being recorded for only 4 localities in over 100 years since it has been described. The ascomata are large and unmistakable, making this species very conspicuous when the reproductive structures are present.

Geographic range

Rickiella edulis has been recorded from 4 distinct localities: South Region of Brazil, in Rio Grande do Sul state, São Leopoldo municipality, in the Araucaria Forest vegetation; Asunción, in Paraguay and two large areas in Argentina: one in Salta, in the Gran Chaco vegetation (Romero et al. 2012), and one in Misiones, in the Atlantic Forest vegetation (Vignale et al. 2015). It probably occurs in additional sites that have similar vegetation.

Population and Trends

The species was first recorded in 1891 in Paraguay. There are 4 known localities: one in southern Brazil, in Atlantic Forest, one in Paraguay, in Gran Chaco and two in Argentina, one in Gran Chaco (Salta) and another one in Atlantic Forest (Misiones), representing 15 collections.

Deforestation in the Atlantic Forest has largely declined over the last two decades. However, it has been heavily exploited, and only 28% of its natural coverage remains, largely composed by forest fragments and secondary forests (Tabarelli et al. 2010, Rezende et al. 2018). The locality in the Atlantic Forest belongs to Mixed Ombrophilous Forest (Araucaria Forest), which has only 13% of its original cover remaining (Ribeiro et al. 2009), almost all severely disturbed and fragmented (Vibrans et al. 2011). Although Misiones is the most preserved fragment of Atlantic Forest in Argentina, only about 17% of the province is in protected areas (Izquierdo et al. 2008). The other two known localities are in Gran Chaco, an extremely threatened biome, suffering from long-term and expanding human occupation and high rates of deforestation (200,000 ha/year) (Gasparri et al. 2008, Gasparri and Grau, 2009, Aide et al. 2013, Volante et al. 2016, Volante and Seghezzo 2018). The native forest on this region is quickly giving way to agricultural activities (Fehlenberg et al. 2017), especially soybeans (Gasparri and Grau 2009, Delvenne et al. 2013).

There is only one record from Paraguay, near Asunción, and that site is probably no longer extant. In Brazil and Argentina it has rarely been collected, even though the species is relatively large and distinctive, and there have been a number of mycological surveys within potential habitats. Thus, the species is considered rare throughout its range. Before deforestation the species was probably broadly distributed but uncommon. Assuming that the there were over 10,000 mature individuals in the past, land use changes over the last 100 years have decreased the population to fewer than 2,000 mature individuals.


Population Trend: Decreasing

Habitat and Ecology

The species is restricted to the now fragmented and scattered Atlantic Forest (Araucaria Forest and Seasonal Semideciduous Forest) and Chaco vegetation. It is a saprotrophic species, growing on dead fallen twigs and logs of unidentified angiosperms, usually that are in an advanced decomposition state. According to fungarium collections, the ascomata are found during the summer (Jan-Feb).

Subtropical/Tropical Dry ForestSubtropical/Tropical Moist Lowland ForestSubtropical/Tropical Moist Montane Forest


Rickiella edulis occurs in the Atlantic Forest and Gran Chaco, both deforestation hotspots. There are many threats that can lead to habitat loss in unprotected areas, especially the intensification of replacing native forests with exotic tree plantations, intensive agriculture, and clearing for pastures, as well as expansion of cities (Izquierdo et al. 2008), which have been exacerbated by government subsidies (Placci and Di Bitetti 2006).

Housing & urban areasAgro-industry farmingAgro-industry plantationsAgro-industry grazing, ranching or farmingUnintentional effects: subsistence/small scale (species being assessed is not the target) [harvest]Unspecified species

Conservation Actions

The main action to prevent the further decline of the species is preservation of the habitat. If in fact the species is edible, as suggested by its specific epithet, it should be investigated as a strong candidate for ex situ conservation initiatives.

Site/area protectionResource & habitat protectionSite/area managementCaptive breeding/artificial propagationAwareness & communicationsPolicies and regulations

Research needed

More surveys are needed to identify other localities and improve knowledge on population trends and ecology. An interesting research need is about its edibility, given its species epithet (edulis). If edible, the environmental factors for producing the ascomata, secondary metabolites and nutritional values of R. edulis should be investigated as well.

Population size, distribution & trendsLife history & ecologyHarvest, use & livelihoods

Use and Trade

The ascomata are suggested to be edible, but there are no data to substantiate this idea.


Aide, T.M., Clark, M.L., Grau, H.R., Lo´pez-Carr, D., Levy, M.A., Redo, D., et al. Deforestation and Reforestation of Latin America and the Caribbean (2001–2010). Biotropica. 2013; 45: 262–271. https://doi.org/10. 1111/j.1744-7429.2012.00908.x

Avigliano, E., Rosso, J.J., Lijtmaer, D., Ondarza, P., Piacentini, L., Izquierdo, M. Cirigliano, A., Romano, G., Bustos, E.N., Porta, A., Mabragaña, E., Grassi, E., Palermo, J., Bukowski, B., Tubaro, P. and Schenone, N. (2019). Biodiversity and threats in non-protected areas: A multidisciplinary and multi-taxa approach focused on the Atlantic Forest. Heliyon, 5(8), e02292.

Delvenne, P., Vasen, F. and Vara, A.M. (2013). The “soy-ization” of Argentina: The dynamics of the “globalized” privatization regime in a peripheral context. Technology in Society, 35, 153–162.

Fehlenberg, V., Baumann, M., Gasparri, N.I., Piquer-Rodriguez, M., Gavier-Pizarro, G., & Kuemmerle, T. (2017). The role of soybean production as an underlying driver of deforestation in the South American Chaco. Global Environmental Change, 45, 24–34.

Gasparri NI, Grau HR, Manghi E. Carbon pools and emissions from deforestation in extra-tropical forests of northern Argentina between 1900 and 2005. Ecosystems. 2008; 11: 1247–1261. https://doi. org/10.1007/s10021-008-9190-8

Gasparri, N.I., & Grau, H.R. (2009). Deforestation and fragmentation of Chaco dry forest in NW Argentina (1972–2007). Forest Ecology and Management, 258(6), 913–921.

Instituto Brasileiro de Geografia e Estatística. 2020. Rio de Janeiro: Instituto Brasileiro de Geografia e Estatística. Disponível em: https://cidades.ibge.gov.br/brasil. Acesso em: 23 de Março de 2020.

Izquierdo, A.E., C.D. De Angelo, and T.M. Aide. 2008. Thirty years of human demography and land-use change in the Atlantic Forest of Misiones, Argentina: An evaluation of the forest transition model. Ecology and Society 13(2): 3. http://www. ecologyandsociety.org/vol13/iss2/art3/.

Pfister, D. H. 1987.The placement of Pezizaedulis in Rickiella (Sarcoscyphaceae, Pezizales). Mycotaxon 29: 329-333.

Placci, G., and M. Di Bitetti. 2005. Environmental situation on the Upper Parana Atlantic Forest ecoregion. In Argentina environmental situation, ed. A. Brown, U. Martı´nez Ortiz, M. Acerbi, and J. Corcuera, 197–210. Buenos Aires, Argentina: Fundacio´n Vida Silvestre Argentina (in Spanish).

Rezende, C.L., Scarano, F.R., Assad, E.D., Joly, C.A., Metzger, J.P., Strassburg, B.B.N., Tabarelli, M., Fonseca, G.A., Mittermeier, R. A. (2018) From hotspot to hopespot: An opportunity for the Brazilian Atlantic Forest. Perspectives in Ecology and Conservation. doi:10.1016/j.pecon.2018.10.002

Ribeiro, M.C., Metzger, J.P., Martensen, A.C., Ponzoni, F.J. and Hirota, M.M. 2009 The Brazilian Atlantic Forest: how much is left, and how is the remaining forest distributed? Implications for conservation. Biol. Conserv. 142, 1141–1153.

Rick J. 1904. Über einige neue und kritische Pilze Süd-Amerikas. Annales Mycologici, 2 (3): 242-247.

Rivers, M.C., Bachman, S.P., Meagher, T.R., Lughanda, E.N., Brummitt, N.A. (2010) Subpopulations, locations and fragmentation: applying IUCN red list criteria to herbarium specimen data. Biodiversity and Conservation, 19(7), 2071–2085. doi:10.1007/s10531-010-9826-9

Romero, A.I., Robledo, G., LoBuglio, K.F. & Pfister, D.H. 2012. Rickiella edulis and its phylogenetic relationships within Sarcoscyphaceae. Kurtziana 37 (1): 79-89.

Spegazzini C. 1891. Fungi guaranitici nonnulli novi vel critici. Revista Argentina de Historia Natural, 1 (6): 398-432.

Tabarelli, M., Aguiar, A. V., Ribeiro, M. C., Metzger, J. P., & Peres, C. A. (2010) Prospects for biodiversity conservation in the Atlantic Forest: Lessons from aging human-modified landscapes. Biological Conservation, 143(10), 2328–2340. doi:10.1016/j.biocon.2010.02.005

Vibrans, A.C., Sevegnani, L. and Uhlmann, A. 2011 Structure of mixed ombrophyllous 40forests with Araucaria angustifolia (Araucariaceae) under external stress in Southern Brazil. Rev. Biol. Trop. 59, et al, 1371–1387.

Vignale, M.V., Grassi, E. & Robledo, G.L. 2015. New record for Rickiella edulis (Ascomycota) from Argentina. Bol. Soc. Argent. Bot. 50 (Supl.): 237237.

Volante, J.N., Mosciaro, M.J., Gavier-Pizarro, G.I., & Paruelo, J.M. (2016). Agricultural expansion in the Semiarid Chaco: Poorly selective contagious advance. Land Use Policy, 55, 154–165.

Volante, J.N., & Seghezzo, L. (2018). Can’t see the forest for the trees: Can declining deforestation trends in the Argentinian Chaco region be ascribed to efficient law enforcement? Ecological Economics, 146, 408–413.

Known distribution - countries

Regional Population and Trends

Country Trend Redlisted