I would be extremely surprised if you found the exact wood you are patching. I think if I needed wood like that I would find flooring that matched in color and cut the width and thickness to dimension with my table saw. When ripping it for thickness cut off the bottom of the board and leave the face alone.
Since it is a patch I would not get involved in adding the tongue and groove but just face nail it with my brad nailer.
I had an old floor in Georgetown, WA DC. where the flooring was old growth quartersawn white oak, an inch and a half wide and a solid quarter inch thick. The entire floor was face nailed. I ended up dismantling an old table which had old oak which matched the floor I needed to repair the floor. I cut the salvaged wood to dimension and did the repair and it worked great.
I would suggest to start looking at engineered wood or furniture for a source of matching wood and mill it to dimension with a table saw. Also an architectural salvage business where they salvage building materials including flooring for just such repairs might also be a good place to look for wood that could be used. Thrift stores like Goodwill are also a possibility for flooring or furniture that could be used.
Some flooring stores and installation companies have left over flooring from installations which might also work. They keep it for repairs too.
Below are pictures of the floor I repaired with wood from the old table. Under the radiator I also had to steam the old wood to complete the repair.