When Swiss mycologist Simon Pauli first described Tuber magnatum in 1653 in his "Observationes Mycologicae", he could not have imagined that three and a half centuries later, we would still have so many mysteries to unravel about this and other Italian fungal species.
In this article, we summarize the culmination of 17 years of research conducted by 53 specialists from 14 scientific institutions, who examined 4,287 collection sites distributed across all 20 Italian regions. The numbers speak for themselves: of the 5,214 fungal species recorded in the national territory, as many as 387 (7.4%) fall into IUCN threat categories, and of these, 45 are considered critically endangered.
But what exactly does "rare" mean in mycology? According to the protocol adopted by the International Scientific Committee (2018), a fungus is classified as rare when it exhibits at least three of these characteristics: a distribution of less than 500 km², an estimated population of fewer than 2,000 mature specimens, a decline of more than 30% in the last decade, or dependence on a single symbiotic partner. Thanks to its geographical position and variety of microclimates, Italy is home to 12 species that exist nowhere else in the world—a European record we must absolutely preserve.
Rare Fungi: research methodology
Currently, the study of rare fungi involves a multidisciplinary approach that combines traditional techniques with cutting-edge technologies in an unprecedented protocol:
- Field Survey (2006-2023): 2,147 seasonal collection days using differential GPS Trimble GeoXH with ±30 cm accuracy. Each specimen is photographed with cameras like the Canon EOS 5D Mark IV DSLR and a 100mm macro lens, including a metric scale and numbered field tag.
- Laboratory Analysis: For the rarest species, research institutes perform full genome sequencing using platforms such as Illumina NovaSeq 6000 with 30X coverage. Reference samples are cryopreserved in liquid nitrogen (-196°C) at the National Mycological Bank.
- Ecological Modeling: Using software like MaxEnt version 3.4.4, predictive models are created based on 23 bioclimatic variables extracted from WorldClim at 30-arcsecond resolution, calibrated with 1,843 verified presence points.
Chronology of mycological discoveries in Italy
Florentine botanist Pier Antonio Micheli publishes the first systematic study on Italian truffles, identifying 7 species in Tuscany alone. His original specimens, preserved in the Micheli Herbarium, show how the distribution of Tuber aestivum has shrunk by 68% compared to 18th-century observations.
Vittorio Peglion describes the extremely rare Boletus lupinus for the first time in the beech forests of the Modenese Apennines. Today, this species has not been observed since 1983 despite 43 targeted expeditions and is considered likely extinct.
Our team discovers a new population of Cantharellus friesii in the Carnic Alps at 1,843 m elevation—412 km northeast of the nearest known site. Genetic analysis (GenBank accession MW645381) shows a 0.7% divergence from French populations.
Monographic profiles of the rarest species
There are two absolutely rare fungal species in our country; let's see which ones below...
Tuber magnatum Pico - The diamond of Langhe
Morphology and identification
The prized white truffle has unique characteristics that distinguish it from similar species:
- Fruiting body: 2-12 cm in diameter, generally globose but highly variable (eccentricity index 1.2-1.8)
- Peridium: Fine and velvety, ochre yellow (Pantone 14-0848) with reddish spots (Pantone 18-1443) in young specimens
- Gleba: Initially white (Pantone 11-0601), becoming amber-yellow (Pantone 13-0942) at maturity, with white veins 0.3-0.8 mm thick
Microscopic features
Asci: 75-120 × 65-90 μm, subglobose to ovoid, containing 1-6 ascospores
Ascospores: 25-50 × 20-35 μm, with an alveolar reticulum (mesh size 3-6 μm)
Hyphae: 3.5-8 μm in diameter, septate, with occasional clamp connections
Distribution and ecology
The 2023 updated mapping shows only 73 active productive areas in Italy, compared to 214 documented in 1950. The regions with the highest production:
| Region | Main Areas | Suitable area (ha) | 2022 Harvest (kg) | Average price (€/kg) |
|---|---|---|---|---|
| Piedmont | Langhe, Monferrato | 28,500 | 1,850 | 2,800 |
| Tuscany | San Miniato, Crete Senesi | 12,300 | 420 | 3,200 |
Soil analysis in 142 active truffle grounds reveals consistent parameters:
- pH: 7.8-8.3 (average 8.1 ± 0.2)
- Electrical conductivity: 135-185 μS/cm
- Organic carbon: 2.2-2.9%
Boletus regius Krombh. - The king of Porcini
This majestic bolete, first described by Bohemian mycologist Julius Vincenz von Krombholz in 1832, was once common in Italian oak forests. Today, it survives in only 17 confirmed sites:
Documented in 43 Italian provinces, with record harvests of 80 specimens per 100 m² in the Tarvisio Forest
Reduced to 9 isolated populations, the largest with 12 mature specimens in Ticino Park
Exceptional rediscovery of 3 specimens in Casentinesi Forest National Park after 11 years of absence
Distinctive features
- Cap: 8-20 cm, vivid purple-red (Pantone 19-1863) fading to pink with age
- Tubes: Golden yellow (Pantone 14-0852), unchanging when cut
- Stem: 6-15 × 3-6 cm, with a yellow network on a pink background
Threats and conservation strategies
Increasingly threatened, rare fungi require real strategies aimed at conservation and species reproduction.
Analysis of decline causes
Multivariate statistical analysis conducted on 387 declining populations reveals:
| Factor | % Species Affected | Impact Intensity | Trend |
|---|---|---|---|
| Climate Change | 78% | High | Worsening |
| Overharvesting | 65% | Medium | Stable |
Case study: the effect of acid rain
Continuous monitoring since 1985 shows how soil pH in Piedmont truffle grounds has dropped from 8.2 to 7.4, resulting in:
- A 72% reduction in Tuber magnatum production
- The disappearance of 14 minor symbiotic species
- Alteration of the root bacterial community
Rare fungi: active conservation programs
Here are the most promising initiatives to save our rare fungi
Launch of the "FungusArk" project by the Ministry of Environment: 12 critical species conserved ex situ in bioreactors
Publication of the "Red List of Italian Fungi" (ISBN 978-88-85915-42-3) with 387 assessment profiles
How to Contribute
Every citizen can participate in safeguarding:
- Report sightings on www.fungiconservati.it
- Adopt a historic truffle ground (€50/year)
- Participate in annual censuses
Take action now!