Question
Answer -
No black knot dose not effect Maples or Birch but the prunus species. There are several canker diseases that cause growths that could resemble the canker of black knot. Here is a web site on one of those. Is this close to what you are seeing?  http://www.glfc.cfs.nrcan.gc.ca/treedisease/eutypella_canker_of_maple_e.html
Without more deatil I can not ID the canker. Sorry!

Hi,

Thanks for your response.  I've checked the link you offered and no sir the only thing that this resembles is black knot and I'm 95% certain it was on some pretty good sized maples and other large deciduous trees... as well as a lot of smaller brush in a wooded area.  I'll try to take some digital photo next time I'm down there and get them to you to look at.  

Answer
If you could send me the digital photos and I will see what I can do with them. Also if you could give me some other location information (if in the U.S.-- State, part of the State you are in ). You can send these to my email at: [email protected]