Agaricus reducibulbus and Agaricus abruptibulbus: Abrupt-bulbed Agaricus mushrooms

In this video, I share a handsome collection of mushrooms in the Agaricus genus. I identify these mushrooms as either Agaricus reducibulbus or Agaricus abruptibulbus, two edible species that look very similar. Unlike other Agaricus mushrooms, Agaricus reducibulbus and abruptibulbus have a bulb at the base of the stem, which make the mushrooms look like they’re wearing stumpy little shoes. I review the features of these two species and discuss the differences between them, concluding this collection is most likely Agaricus reducibulbus because it doesn’t feature the yellow staining reaction that is a common feature of Agaricus abruptibulbus.

The bulbous stem base makes these specimens look somewhat like Amanita mushrooms at a casual glance, because Amanitas are characterized by bulbs, sacs of tissue, ridged zones, or other fancy business at the base of their stems. But like other members of the Agaricus genus, Agaricus reducibulbus and A. abruptibulbus have gills that turn pink and then dark chocolate-brown as they mature, which reveals their true nature.

I also explain how to identify Agaricus mushrooms as a genus and recognize mushrooms that are categorized as secondary decomposers. Secondary decomposers grow on the ground in leaf litter, poop, and other substrates that are already well on their way to becoming soil. Many times, mushrooms that grow on the ground are mycorrhizal and grow in association with a tree or plant partner, so I demonstrate how to recognize the mycelium that tends to clump and cluster around the base of secondary decomposers like Agaricus campestris aka the meadow mushroom and Clitocybe nuda, the blewit mushroom.