Taxonomic reexamination of Auricularia specimens based on updated morphological criteria

Auricularia specimens deposited in the National Museum of Nature and Science, Japan, were observed to reexamine their species identification based on updated taxonomic criteria, and to verify the taxonomy and distribution of Auricularia spp. in Japan. Four of the ten specimens previously identified as A. auriculajudae were reidentified as A. americana (1), A. cornea (1), and A. villosula (2) based on morphological criteria such as medullae, abhymenial hairs, and basidiospores. The remaining six specimens could not be identified at the species level due to the lack of distinguishing morphological characteristics. Two of the five specimens previously considered A. minor were identified as different species due to basidiospore size discrepancy, but the remaining two specimens and the type specimen were in poor condition, and their basidiospores could not be properly observed. Three of the nine specimens previously identified as A. polytricha were reidentified as A. cornea based on morphological criteria. The remaining six specimens were not identified as A. polytricha. The type specimens of A. polytricha f. leucochroma and A. polytricha f. tenuis were in poor condition, and their basidiospores could not be properly observed. Reexaminations of existing specimens based on recent taxonomic criteria will contribute to updating the taxonomy and distribution of Auricularia spp. in Japan.
国立科学博物館に収蔵されているAuricularia標本の形態を観察し，近年の分類学的基準に基づく種同定および本属菌の日本における分類と分布の再検討を行った。その結果，A. auricula-judaeとされていた10標本中，4標本がそれぞれA. americana（1），A. cornea（1），A. villosula（2）に再同定された。残りの6標本は，種の識別に有用な形態的特徴がみられなかったため，種同定には至らなかった。Auricularia minor とされていた5 標本のうち，2標本は本種とは別種と考えられた。残りの2標本とタイプ標本は状態が良好ではなく，十分な担子胞子の観察ができなかった。Auricularia polytricha とされていた9標本のうち，3標本はA. corneaに再同定された。残りの6標本はA. polytrichaやA. nigricansとは別種であると考えられた。Auricularia polytricha f. leucochromaとA. polytricha f. tenuisのタイプ標本は状態が良好ではなく，担子胞子の観察ができなかった。近年の分類基準に基づいて過去の標本を再検討することにより，日本におけるAuricularia spp.の分類と分布情報を更新することができるだろう。