- Genus 2: Suillellus
- Genus 3: Boletus
Species: subvelutipes (see Science Notes)
- Species 2: austrinus (This may be an independent southern species – it’s listed as such in online sources – but it doesn’t appear in North American Boletes and the best description I’ve found is “B. subvelutipes with purple hairs/tufts on the stem instead of yellow or red.” Expect “austrinus” to be revived as one of the species names for this group once a broad DNA study has been completed to tell us how many species there are. We are folding the names together until then.
Common Name: “Red Mouth Bolete”
Tells: Red/brown/orange pores instantly stain blue, as does the bright yellow flesh. Blue-staining red/yellow stem has no netting, and may have velvety hairs at the base.
Other Information: Found under hemlock and occasionally another conifer; the lookalike oak-lover is genetically distinct. Flesh has sometimes been reported as tasting a bit acidic, but that is not a reliable characteristic and may actually indicate one of the as-yet-unnamed subspecies (see Science Notes). The hairs at the stem base (which look more like velvet than hairs) are also unreliable. Specimens showing the velvety hairs typically have a yellow fuzz when young, which quickly turns dark red.
Edibility: The traditional instruction in America was clear: “Avoid the red-pored blue-stainers like this one because they are known sick makers.” That came under question beginning in the 2010’s as DNA evidence proved that these mushrooms are quite distinct from the Rubroboletus and Suillellus genera that contain the true “Satans Boletes”. The close relatives of these species (see the Science Notes) are not only edible, but good. Indeed the all-but-lookalike European mushroom now known as Sutorius luridiformis (f/k/a Boletus discolor) has been greedily sought forever as the choice “Scarletina.” Your mileage may vary. For site purposes it is being promoted to “iffy” as a reflection of the ongoing debate, but with the proviso that all the old lore would disagree.
Science Notes: The species was originally described in 1889 by the legendary mycologist Charles Horton Peck. After 1889 the description slowly morphed until it really came to mean, “That common red-pored, blue-staining, non-reticulated mushroom in the East.” In other words, it was reliably identified by genuine experts with such a broad brush that it was sure to be a series of similar looking mushrooms that all go by the same name depending on where you are. Recent DNA testing has confirmed this. This site chooses to limit the name “subvelutipes” to the hemlock-lover because (a) that is a distinct genetic species, (b) your author participated in an effort to find an “epitype” to replace Peck’s original “holotype” because that sample no longer has usable DNA, (c) the general location where we found it was dominated by hemlock, and (d) the specific finds were under a grove of hemlock.
The parallel, oak-loving red mouths appear in the books under a series European names such as discolor and luridiformis, along with poorly described American names like subluridellus. Unpublished DNA work suggests 4-5 separate species in that category that will ultimately require “holding names” until the scientific method plays out
Finally, there is an undescribed species found in the Southwest mountains that is either subvelutipes or a good lookalike. We are waiting for DNA results before expanding the published geographic range to include those finds.
- NH4OH (Ammonia): Cap skin turns mahogany-red. Blue-stained cap flesh turns rusty orange.
- KOH: Cap skin turns mahogany-red. Blue-stained cap flesh turns rusty orange.
- FeSO4 (Iron Salts): Cap skin turns grayish- to dark olive-green. Blue-stained cap flesh turns yellow orange.