Two new species of Lactifluus subgenus Lactifluus were discovered during a three-year monitoring of the ectomycorrhizal fungi in a tropical oak forest from central Veracruz, Mexico. Systematic sampling of basidiomes allowed recording of the morphological variation of fruit-bodies in different growth stages along with their fructification season. Both new species were distinguished, based on macro- and micromorphological features and on molecular data. A phylogenetic analysis of a concatenated nuc rDNA ITS, D1 and D2 domains of nuc 28S rDNA (LSU) and the 6-7 region of the second largest subunit of the RNA polymerase II (rpb2) sequence dataset of species of Lactifluus is provided. In the phylogeny inferred, one of the new species is sister to L. dissitus Van de Putte, K. Das & Verbeken and the other belongs to the group of species of L. piperatus (L.) Kuntze, sister to an unidentified species from U.S.A. The studied taxa grow under Quercus oleoides in the study site. The species are presented and illustrated here.

中文翻译：

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来自墨西哥东部热带栎属森林的两个新乳杆菌属（真菌，Russulales）。

在对墨西哥韦拉克鲁斯州中部的热带橡树林进行为期三年的外生菌根真菌监测期间，发现了两个新的乳杆菌属乳杆菌属。系统地对basidiomes取样可以记录不同生长阶段的果体的形态变化以及它们的果实​​化季节。根据宏观和微观形态特征以及分子数据，对这两个新物种进行了区分。提供了一个串联的nuc rDNA ITS，nuc 28S rDNA（LSU）的D1和D2结构域以及乳杆菌属物种的RNA聚合酶II（rpb2）序列第二大亚基的6-7区的系统发育分析。在系统发生学上，一个新物种是L. dissitus Van de Putte，K。Das＆Verbeken的姐妹，另一个属于L.物种。piperatus（L.）Kuntze，来自美国的一个未知物种的姐妹。被研究的类群在研究地点的油栎（Quercus oleoides）下生长。此处介绍并说明了该物种。