This mushroom is possibly a Lactarius hepaticus, known in English as Liver Milkcap.
The first time I found one, it was alone, apparently growing on wood (photos below). Based on its physical characteristics, I had thought it could be a Lactarius, especially because of the white latex it releases. However, since Lactarius are associated with the roots of pine trees, I thought it was some other genus.
Posting in the Facebook group “Cogumelos do Brasil” and asking for help, mycologist Denis Zabin suggested this identification and explained that the mycelium can grow on other substrates that are close to the Pinus, such as pine cones and pseudostems of the Xaxim fern (Dicksonia sellowiana), and in this case some piece of decomposing wood. I found it very interesting, and in fact there was a Pinus near this wood.
Some other members of the group also suggested that it could be some other species of Lactarius, another suggestion was Lactarius subdulcis.
After this encounter, we saw them several times in other areas, always with Pinus, usually in Autumn and Spring.
Some information classifies the species Lactarius hepaticus as edible but with a spicy taste, which can be unpleasant for some people. It’s certainly not like it’s “cousin” which is also commonly found here and generally beloved, Lactarius quieticolor.
As I still have no certainty about the identification, I have never tried it, as there are some species of this genus that are not edible.
📸 Pictures made in São Francisco de Paula, Rio Grande do Sul (Serra Gaúcha, South of Brazil).