You have me going on this one !!!!??? As I have been scratching my brain and can no longer remember.
We used a "Yellow Pine" back in the late 50's early 60's building the 65 foot fishing boats to plank the bottoms, Keel, and Stem.
I think it was called "Southern Long Leaf Yellow Pine" and came from North Carolina area. But the lighter colored rings were much darker than your piece and the dark rings where "hard as nails" !!!! So, that lumber must have come from some pretty big trees !!!
It was very hard/dense and apparently the marine life/worms etc. did not like it !!! It had the feel of being "oily" and maybe was sap, but didn't have any "sticky goo" oozing from it !! Must have been 1/4 sawed since never encountered any "raised grain" on the surface. Also was basically "clear" very rarely did you encounter a knot. Also, the boards were 2-1/2 inch thick X 6 to 8 inches wide and 12 or 16 ft. long. About all the weight you wanted to handle
I used to work on Saturday's when in High School, and at times alone. Fashioning the plank (they were shaped, not 'straight boards') was about all the weight you wanted to try to handle on a table saw and shaper. Then "hand planing" the "corking bevel" on the edges was a tough job with a "razor sharp" plane !!!
I had a "real Rube Goldberg" approach to getting the plank up and clamped into place to fasten when by myself. At 4 ft.++ above ground, all you needed was one of those suckers to come down on your head "just once" and you "quickly beefed up your lifting mechanism" !!!!
Your piece looks like it came from a quartered log. Have fun with the lathe, and "thanks for the memories" !!!!