Ectomycorrhizal symbiosis appears extensively in the Northern Hemisphere, where Mediterranean ecosystems constitute an important ecological area of considerable biodiversity value. Littoral sand dunes are among high-risk habitats, and ectomycorrhizal lifestyle contributes significantly to supporting life in such regions. Mallocybe heimii (Bon) Matheny & Esteve-Rav. (Inocybaceae, Basidiomycota) and the very similar M. arenaria (Bon) Matheny & Esteve-Rav. grow in poor, usually sandy soils, in association with angiosperms or gymnosperms. Basidiomata originally identified under these names were collected from littoral sand dunes of Greece, and their morpho-anatomical characteristics were examined in conjunction with material derived from other European regions. Sequences from basidiomata and root tips corresponding to the nuclear rDNA internal transcribed spacer region (ITS) and large subunit (LSU) were obtained and analyzed. Phylogenetic results demonstrated that material identified as M. heimii or M. arenaria form a single well-supported group, while M. agardhii (N. Lund) Matheny & Esteve-Rav. is confirmed to be distinct from M. arenaria (the latter was initially described as a variety of the former, i.e., I. agardhii var. arenaria Bon). A detailed tree of the genus Mallocybe was generated on the basis of concatenated ITS and LSU sequences, and relationships of selected taxa are discussed in the light of morphological and sequence data. In addition, the first morphotype descriptions of M. heimii ectomycorrhizae with Cistus creticus L. and Pinus halepensis Miller are hereby provided. Both morphotypes exhibited the typical characteristics of Inocybe/Mallocybe ectomycorrhizae; however, differences were noted, the most significant being the presence of clamps on mantle hyphae and the type of anastomoses.

外生菌根共生广泛出现在北半球，那里的地中海生态系统构成了具有相当生物多样性价值的重要生态区。沿海沙丘是高风险栖息地之一，外生菌根的生活方式对支持这些地区的生活做出了重大贡献。Mallocybe heimii (Bon) Matheny & Esteve-Rav。( Inocybaceae , Basidiomycota) 和非常相似的M. arenaria(Bon) Matheny & Esteve-Rav。生长在贫瘠的，通常是沙质土壤中，与被子植物或裸子植物一起生长。Basidiomata 最初以这些名称确定，是从希腊的沿海沙丘中收集的，并结合来自其他欧洲地区的材料检查了它们的形态解剖特征。获得并分析了与核 rDNA 内部转录间隔区 (ITS) 和大亚基 (LSU) 相对应的担子纲和根尖序列。系统发育结果表明，鉴定为M. heimii或M. arenaria 的材料形成了一个支持良好的组，而M. agardhii (N. Lund) Matheny & Esteve-Rav。被证实与M. arenaria 不同（后者是最初被描述为多种前者，即我。agardhii变种根结线虫BON）。根据连接的 ITS 和 LSU 序列生成了Mallocybe属的详细树，并根据形态学和序列数据讨论了所选分类群的关系。此外，特此提供了M. heimii外生菌根与Cistus creticus L. 和Pinus halepensis Miller的第一个形态型描述。两种形态型均表现出Inocybe / Mallocybe的典型特征外生菌根；然而，注意到了差异，最重要的是在地幔菌丝上夹子的存在和吻合的类型。