The genus Atheniella is characterized by fairly small to medium-sized, brightly coloured to whitish, species with non-amyloid spores, smooth, fusiform cheilocystidia, presence of pleurocystidia, diverticulate hyphae of the pileipellis, and smooth hyphae of the cortical layer of the stipe. It was formerly recognized as Mycena sect. Adonideae Quél.
Maas Geesteranus (1990) included M. ochrogaleata in the section, and this was followed by Robich (2003). Antonín & Noordeloos (2004), however, recognized it as a member of the genus Hemimycena. This view was followed by Emmett et al. in Knudsen & Vesterholt (2008). Lüderitz & Lehmann (2018) treated Hemimycena delectabilis as Atheniella delectabilis (Peck) Lüderitz & H. Lehmann. They also introduced the new species Atheniella ulmariae H.Lehmann & Lüderitz, which was found on Filipendula ulmaria and resembling a very small A. flavoalba. Among the diagnostic characters were the small size, a yellowish papilla, 2-spored basidia, and absence of clamps.
| 1. Stipe not rooting, not turning dark brown with age |
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2. Pieleus whitish, ivory or yellow-white : A. flavoalba |
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2. Pileus coral red, pink-salmon, scarlet or orange red, apricot pink, yellow salmon to pale citrine or bright yellow |
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3. Pileus with no trace of yellow, nor turning yellowish when fading, spores fairly broad: A. adonis |
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3. Pileus turning yellow with age, spores narrow: A. flavoalba (pink form) |
| 1. Stipe rooting, turning dark brown from base upwards: A. leptophylla |
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