This caption particularly applies to the dried mushrooms in the photo set, which were photographed today, 4 days after collection:
These mushrooms were collected in the same area (intermingling within about a 10 foot diameter) in oak woodland. They were very similar, except the ones on the far right have the distinctive, strong odor of maple syrup. The ones on the left have a faint smell of maple syrup and on the average a thicker stipe (both fresh and dried). I'm calling the mushrooms on the left Lactarius rufulus and the ones on the right Lactarius rubidus. This sample of L. rubidus also was generally darker than L. rufulus. While fresh the difference wasn't as great as when they dried. Also, all of these mushrooms were starting to dry out in the field. Though faint L. rubidus already was developing its sweet, maple syrup odor. L. rufulus, however, had little odor at all in the field; it did not develop it's faint, sweet odor of maple syrup until it was dried out completely. Lastly, note that in the photo of the dried mushrooms with the stipes in the foreground that L. rubidus tended toward hollow stipes and L. rufulus tended toward a solid stipe. Just to clarify the last two photos of this set of photos of the dried mushrooms on a paper towel each have both types of lactarius, the left side of the paper towel being L. rufulus (that's what I think, anyway).
I think so. . . but probably not.
On side of track.
The Russulaceae are a family of fungi in the order Russulales. According to a 2008 estimate, the family contains 1243 species. Its species typically have fruit bodies with friable, chalk-like stalks, that break with a distinct crack, somewhat like a carrot but with porous flesh (see below). Microscopically, the cells are not all long thin hyphae, which would provide strength and more fibrous appearance when broken. Instead, the flesh contains also many large spherical cells ("sphaerocysts"),...