Molecular studies of sphagnicolous arrhenias in Newfoundland and Labrador (NL) revealed four clades in Arrhenia, three obligate (two scaly capped and one smooth-capped) and one facultative (smooth-capped) sphagnophiles. Critical nomenclatural review of 16 names used for omphalinoid sphagnicolous taxa in the past left five suitable to apply to this group. One scaly capped obligate sphagnophilic clade contained the type for Arr. gerardiana and the other, the type for Clitocybe gerardiana var. fusca; the latter we introduce as the novel species Arr. bigelowii. It differed from the first by longer spores and a darkening reaction in 10% of collections. The smooth-capped third obligate sphagnophilic clade contained the types of Agaricus telmatiaeus and Omphalina fusconigra; we recombined it as Arr. telmatiaea. This is the darkest species of the group, with a more northern distribution in NL. The facultative sphagnophile was identified as Arr. philonotis, a lighter smooth-capped species also with a more northern distribution in NL. Unexpectedly, we also collected an unidentified smooth-capped facultatively sphagnophilic species of Omphalina of the O. pyxidata complex. All five species are distributed in both Europe and North America. We describe each species of Arrhenia with a sequenced type, providing new type material where needed. Overall, this study adds new sequences from over 80 specimens of sphagnicolous arrhenias to the two existing in GenBank when we began in 2006, 11 new sequences of the unidentified species of Omphalina, and several other arrhenias.

纽芬兰和拉布拉多 (NL) 的 sphagnicous arrhenias 的分子研究揭示了 Arrhenia 的四个进化枝，三个专性（两个鳞状覆盖和一个光滑覆盖）和一个兼性（光滑覆盖）sphagnophiles。过去，对 16 个用于 omphalinoid sphagnicolous 分类群的名称进行了批判性命名审查，留下了 5 个适用于该组。一个有鳞片的专性嗜泥菌进化枝包含Arr 的类型。gerardiana和另一个，Clitocybe gerardiana var 的类型。福斯卡; 后者我们作为新物种Arr 引入。比格罗伊. 它与第一个不同之处在于更长的孢子和 10% 的收集物的变黑反应。光滑覆盖的第三个专性嗜泥菌进化枝包含姬松茸和黑斑菇的类型；我们将其重新组合为Arr。地草属。这是该组中最黑暗的物种，在荷兰分布更北。兼性嗜泥菌属被鉴定为Arr。philonotis，一种较轻的光顶物种，也分布在荷兰北部。出乎意料的是，我们还收集到了O. pyxidata的Omphalina的一种身份不明的光滑帽兼性嗜泥菌种。复杂的。所有五个物种都分布在欧洲和北美。我们用排序的类型描述每种Arrhenia物种，在需要时提供新的类型材料。总体而言，这项研究从 2006 年开始时在 GenBank 中现有的两个样本中添加了来自 80 多个 sphagnicous arrhenias 标本的新序列、11 个未鉴定的Omphalina物种的新序列，以及其他几个 arrhenias。