Tuber melanosporum

CHOIROMYCES MAGNUSII (Mattirolo) Paoletti 1889

in Saccardo's Syll. fung. VIII: 901
Choiromyces magnusii

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Terfezia magnusii Mattir Mem. Accad. Scienze, Torino, ser. 2 37: 16 (1887)


Choiromyces gangliformis Vittad., (1831) sensu Ceruti, Icon. Mycol. Bresadola 28 suppl. 2: 19, tab 19, (1960) non Vittadini

Macroscopic characters:

Ascomata: hypogeous or subhypogeous, subglobose, irregularly lobed, gibbous, deeply sulcate, 2-8 (-12) cm in size, smooth, initially whitish, becoming ochre or brown, with adhering soil

Gleba: hard, whitish at first, brown at maturity, marbled with sterile, white, sinuous veins, no completely surrounding the fertile areas

Odour: faint, distinctive

Taste: mild, pleasant, not much persistent


They are highly prized in parts of Extremadura (Spain) and Andalusia (Spain), where Choiromyces magnusii is known as “criadilla jarera”


It is a spring species that grows in dry, acid soil and always associated with Cistus ladanifer. Although its development is hypogeous, you can detect its presence through the cracks forming in the soil as they grow


Although Ceruti synonymizes Choiromyces gangliformis Vitt. with Choiromyces magnusii, its strong, unpleasant odor, with ripening period in Summer and Autumn is more like Choiromyces meandriformis. Vittadini himself admitted that both species are hardly different and that Choiromyces gangliformis could be considered a particular form of Choiromyces meandriformis, rather than different species


Choiromyces magnusii spores

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Microscopic characters:

Asci: elongate-clavate, arranged among paraphyses in an irregular hymenium, 150-160 (200) x 40-60 µm, thick-walled (up to 2,5 µm thick), 8-spored, not stained in Melzer’s Reagent

Paraphyses: hyaline, septate, cylindric, up to 8 µm diam. towards the apex.

Ascospores: 17-25 µm, globose, yellow at maturity, ornamented with low (<1 µm), hemispherical warts, giving them a golf ball-like appearance

Peridium: 100-200 µm, composed of interwoven, hyaline, yellow in the outermost layers, more or less inflated hyphae


Antonio RodríguezAntonio Rodríguez
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