Citation: Sp. pl. 2: 1176 (1753)
See comments. This is still a valid name for a (narrow) genus, even it is had been misapplied and even if some people continue to misapply it.
As it has been known for several years, the old genus Boletus is in the process of being broken up. In the strict sense, this genus should be limited only to porcini-type boletes, typified by the good old B. edulis. While there are still many species currently in Boletus that don’t really belong there, as they are clearly not “bolete royalty” as per the recent phylogenetic studies of the Boletacea, it may take many years to transfer them out of Boletus into the appropriate genera. The bottom line is that naming your unknown Boletus sp. as Boletus L. no longer makes any sense — hence the next best thing, the family level (Boletaceae). For any uncertain taxa in the porcini clade that evade identification, please use Boletus sensu stricto nom. prov. Dentinger.
Will these mushrooms
happen to be edible?
My point is that it seems presumptuous at this point to call anything Boletus sp. that isn’t pretty clearly in the same clade as Boletus edulis (the type according to MycoBank). My expectation for the molecular work is similar to Christian where Boletus will be essentially be restricted to the Procini. Of course there will probably be a few surprises, but if anything that would support the convention of using “Boletaceae sp.” rather than “Boletus sp.” until there is greater clarity.
There are a couple of key studies at the moment. Wait and see. It is going to be dynamic at least from the data that I can derive based on my own analysis of Boletaceae. That one on that picture above will probably not be Boletus s.s.D.
In the future will likely only include the Porcini – those with stuffed pores when young. So, yeah, most things that aren’t big stately edibles are better called Boletaceae (I think).
Recently (Dec. 2011), I’ve been working on figuring out what content can reasonably be shared with other sites (EOL specifically). In this case, it seems like the genus Boletus is being used as a bit of a catch all for organisms that are probably better described as Boletaceae. In the short term I’ve disabled exporting images that are identified just as “Boletus sp.”. My thought is that these should all be identified as “Boletaceae”.