A perplexing Hygrocybe that seems to shift colors with the environment. When observed in a semi-dry state the next day, the pileus was dark maroon and the gill edge even appeared green! Looking at other photos of H. prieta with the more typically green hymenium and dark pileus, I am convinced it is that. It is possible that the fresh specimens like this one are more brightly pigmented, or it could be a color variety or just a closely related taxon. Microscopically the dimorphic spores fit the measurements of H. prieta in Lodge (1990) and it keys out to this taxon. H. naranjana is discussed as a taxon that closely resembles H. prieta, and the colors of the dry specimen match the illustration in Dennis (1970) almost perfectly. I would not be surprised if they are synonymous.

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Image #4: H. naranjana in Dennis (1970)

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Originally posted to Mushroom Observer on Nov. 21, 2022.

These queens are not from the same colony, but are independent foundresses from domatia of sapling Vachellia drepanolobium trees, placed together here for a photo. They are defending the pupae of parasitoid wasps which ate their respective broods.

Contents of Vachellia drepanolobium domatium. C. mimosae colonies are often polygynous - this domatium had 3 living queens, two of which had been completely delimbed (but were still alive) and the other (bottom left) was missing legs. This may have occurred due to adversarial interactions between queens or could have been done by workers.

Contents of Vachellia drepanolobium domatium collected for research. Note the presence of a winged gyne-worker 'intermediate' which is yet unrecorded for this species. These intermediates may serve as an additional third 'caste' which lays unfertilized eggs a la C. smithi and a few other Crematogaster species (see Peeters et al. 2013 DOI: 10.1016/j.asd.2013.02.003)

Myrmecophile living among Crematogaster mimosae ants in Vachellia drepanolobium domatium. Cropped and enhanced photos added to assist ID determination. Probable ID: Hockingia curiosa, a known mimic and myrmecophile of C. mimosae (see Hocking 1970 and references listed in comments)