Tuber aestivum Vittadini
Monographia Tuberacearum 38, Tab. II fig. IV (1831)
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Synonyms:
Tuber albidum Cesalpino (1583), De plantis libri XVI 616 sensu Fries (1823)
Tuber cibarium Sowerby (1797), Colored figures of English fungi or mushrooms, London, t. 309
Tuber nigrum Allioni (1785), Flora pedemontana 2, 366 sensu Vittadini (1831)
Tuber albidum Cesalpino: Fries (1823), Systema Mycologicum 2, Pt. II: 291
Tuber blotii Deslongchamps (1824), Mém. Soc. Linn. Calvad. 47, f. 1-3
Tuber uncinatum Chatin, C. R. hebdom. Acad. Sciences 104: 1132 (1887); La truffe 55, t. 7 f. 1 a-e
Macroscopic characters:
Ascomata: hypogeous, subglobose, 2-9 cm, blackish-brown to black, conspicuously warted. Warts 3-12 mm across, pyramidal, 4-6-sided, often depressed at the apex, vertically fissured, usually with fine horizontal striae.
Gleba: firm, solid, white when immature, becoming light brown, dark brown at maturity, marbled with numerous, thin, white, meandering, branching veins that do not change colour when exposed to the air.
Odour: slight and pleasant at first, like roasted malt, becoming strong, seaweed-like with age.
Taste: mild, reminiscent of nuts (walnuts, hazelnuts)
Habitat
Although Tuber aestivum can also be found in the same locations as Tuber melanosporum (well-drained, aerated calcareous soils with high porosity), Tuber aestivum tolerates more compact and clayey soils and typically grows in sunny spots (unlike Tuber uncinatum, which is always found in shaded areas). Tuber aestivum inhibits plant growth and produces more conspicuous "burns" than Tuber melanosporum. Summer truffles develop relatively close to the surface and can betray their presence through cracks in the soil. They are sometimes found beneath leaf litter. They are usually harvested from May to July, but can be found through to December if moisture conditions are favourable. Tuber aestivum is associated with the roots of several trees: oaks (Quercus), beeches (Fagus sylvatica), poplars (Populus), hazels (Corylus), pines (Pinus) and lindens (Tilia).
Notes:
Molecular analysis has shown no differences between Tuber aestivum and Tuber uncinatum. The differences in taste, odour and spore morphology are attributable to ecological factors.
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Microscopic characters:
Asci: globose to subglobose, sessile or short-stalked, 60-110 x 50-70 µm, 1-6-spored (usually 3-4-spored).
Ascospores: 20-45 x 18-35 µm excluding ornament, size variable depending on number of spores in the ascus, Q range = 1,21-1,37, ellipsoid to subglobose, yellow, translucent, ornamented with a coarse irregular reticulum 3-5 µm high, meshes variable, usually 3-5 across width of spore and often with incomplete secondary crests inside.
Peridium: pseudoparenchymatous
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Antonio Rodríguez trufamania@gmail.com antonio@trufamania.com |