MICOLOGIA, di Salvatore Saitta

Indice - Index

Lactifluus rugatus (Kühner & Romagn.) Verbeken
Lactarius rugatus Kühner & Romagn.

Il Lactarius rugatus è stato recentemente inserito nel genere Lactifluus. Alcuni approfondimenti tratti dal sito della Ghent University:

"Russulaceae is one of the largest families of ectomycorrhizal fungi that plays a dominant role in many vegetations worldwide. The core of this family consists of two genera, Lactarius and Russula, both described from Europe two centuries ago as clearly recognizable agaricoid genera. However, recent research (Buyck et al., 2008) demonstrated that the traditional classification of Russulaceae into these two genera is not supported. Instead, the family consists of four mainly agaricoid genera and includes some corticioid species. In one of these genera (Multifurca), some rare representatives of the former Lactarius and Russula are united. The rest of Russula is supported as a monophyletic group. Lactarius, notwithstanding its striking feature of exuding milk or latex (thus: the milkcaps) which always seemed a good synapomorphic character, is paraphyletic and is split in two genera: Lactarius and Lactifluus. Based on morphological and molecular characteristics, Lactifluus seems the most variable out of the four Russulaceae genera. Lactifluus mainly consists of tropical species and recent studies discovered large cryptic diversity within the genus (Stubbe et al., 2010; Van de Putte et al., 2010). Morphologically, this genus is characterized by the complete absence of zonate and viscose to glutinose caps, and it contains many species with veiled and velvety caps and all known annulate species (Buyck et al., 2008). Lactarius on the other hand, has a more temperate distribution, with many cold-adapted species and contains the typical zonate and viscid to glutinose milkcaps. Our present knowledge results in a large genus Lactarius with about 75% of the milkcaps and a smaller genus Lactifluus, but the real number of species in Lactifluus might be higher due to cryptic diversity, which seems to be absent in Lactarius. Our hypothesis is that Lactifluus evolved genetically faster but is morphologically more stable, while morphological variation is more common in the genetically slower evolving genus Lactarius. The speciation-extinction dynamics of both genera are clearly different. These discrepancies have strongly influenced the evolutionary history of both genera."

Osservazioni sulle raccolte fotografate
Le raccolte sono state determinate dal quadro macro-microscopico e dalla reazione al Solfato di Ferro; per la raccolta in foto 2 non è stata fatta microscopia, ma essa è stata rinvenuta nel medesimo luogo della raccolta in foto 3 che è stata studiata in maniera approfondita. Si distingue dal gruppo di Lactifluus volemus per la reazione al Solfato di Ferro che è rosata invece che grigio-verde, per le spore ellissoidali piuttosto che quasi sferiche e per la mancanza di cistidi imeniali.

Foto 3 [IMG8428] - MCVE 31388

- Canon EOS 7D, ob. EF-S 60mm f/2.8 Macro USM
Monti Peloritani, 350m [P7], 03.XI.2018
Copyright © 2018 Salvatore Saitta