Department of Plant and Microbial Biology, University of California at Berkeley, Berkeley, California 94720.
Mycologia. 2013 Sep-Oct;105(5):1275-86. doi: 10.3852/12-391. Epub 2013 May 24.
Based on morphology, fungal species have been considered widespread and as a result names of species from Europe or eastern North America were applied to species in western North America. However, DNA sequences have shown that many western taxa are different from their European counterparts; one such case is presented here. Comparisons of ITS and LSU rDNA sequences from ectomycorrhizal root tips and ascomata of specimens identified as Helvella lacunosa from North America, Europe and Asia revealed that the taxa from western North America and Mexico formed a well supported clade different from the eastern North American, European and Asian taxa. Within this western North American clade there are at least four taxa. Here we describe two of these western taxa as new species: Helvella vespertina and Helvella dryophila. Helvella vespertina is a bigger version of H. lacunosa, is variable in hymenial color and shape and forms ectomycorrhizae with conifers; it fruits typically Oct-Jan. Helvella dryophila is characterized by a dark almost black, squat pileus, a light stipe when young, medium size and forms ectomycorrhizae with Quercus species; it fruits Jan-Jun. Due to insufficient material, the two other Helvella taxa are discussed but not formally described here. We also examined the Hypomyces and other mycoparasites associated with the ascomata of Helvella species and discuss misleadingly labeled sequences in public databases.
基于形态学，真菌物种被认为分布广泛，因此欧洲或北美东部的物种名称被应用于北美西部的物种。然而，DNA 序列表明，许多北美西部的分类群与其欧洲同类不同；这里就提出了一个这样的例子。对来自北美的、欧洲的和亚洲的外生菌根根尖和子囊壳的 ITS 和 LSU rDNA 序列进行比较，鉴定为北美、欧洲和亚洲的 Helvella lacunosa 的标本表明，来自北美的和墨西哥的分类群形成了一个支持良好的分支，与来自北美东部、欧洲和亚洲的分类群不同。在这个北美西部的分支中，至少有四个分类群。在这里，我们将其中两个西部分类群描述为新种：Helvella vespertina 和 Helvella dryophila。Helvella vespertina 是 Helvella lacunosa 的较大版本，在子实层颜色和形状上具有变异性，与针叶树形成外生菌根；它的果实典型的在 10 月至 1 月之间。Helvella dryophila 的特征是深黑色、矮胖的菌盖，年轻时菌柄颜色浅，大小中等，与栎属植物形成外生菌根；它的果实从 1 月至 6 月之间。由于材料不足，另外两个 Helvella 分类群在这里仅进行讨论而未正式描述。我们还检查了与 Helvella 物种的子囊壳相关的 Hypomyces 和其他真菌寄生物，并讨论了公共数据库中标记错误的序列。
