This study aims to resolve taxonomic uncertainties and establish an ecological baseline for four key Boletaceae taxa (Boletus aereus, B. reticulatus, Xerocomus badius, and the endemic B. mamorensis) in the declining Mediterranean cork oak (Quercus suber) forests of north-western Morocco. To achieve this, we conducted systematic (2004–2010) and opportunistic (2011–2022) field surveys across the Maâmora and Khmiss-es-Sahel forests, employing macroscopic characterization and quantitative micro-morphological analysis of basidiospores, basidia, and cystidia from representative fresh basidiomes. Our quantitative analysis revealed substantial morphometric overlap between B. mamorensis (spore quotient Q = 2.5–4.1) and B. aereus (Q = 2.5–3.9), suggesting that the characteristic radicating stipe of B. mamorensis may simply be an ecomorphological adaptation to sandy substrates. Furthermore, X. badius (Q = 1.8–3.7) is documented here as a new habitat record in Khmiss-es-Sahel, and we conclude that recent severe droughts (<350 mm/year rainfall) have heavily suppressed fruiting, exacerbating population declines from overharvesting. A primary limitation of this study is its reliance on historical morphometric data without modern molecular phylogeny (DNA barcoding) or permanently preserved exsiccata, meaning the proposed taxonomic proximity between B. mamorensis and B. aereus remains a preliminary hypothesis requiring future molecular validation. Despite this, the findings offer significant practical value by emphasizing the urgent need to structure local commercial fungal harvesting and implement controlled ectomycorrhizal inoculation of Q. suber nursery seedlings to support sustainable forest regeneration. Ultimately, the originality and significance of the results lie in providing a rare, long-term ecological evaluation of a highly prized endemic fungal resource, thereby establishing a vital foundation for the conservation of Moroccan forest biodiversity against escalating anthropogenic and climatic pressures.