Question
Trying to figure out whats going on with two maples I have.  The last three years, fewer and fewer branches are leafing in spring and the trunk and branches have thousands of very small bumps pretty much everywhere you look.  

Answer
Hi Dave,

I cannot tell from your description exactly what is going on, but there is a symptom you describe which is characteristic of a canker disease.  Silver maples are susceptible to this canker disease caused by fungi of the genus _Cytospora_.  I have listed some of the symptoms below.  If any of these sound familiar upon closer examination of your maples, then you are probably dealing with cytospora canker.  (Some of the oozing characteristics are not visible on silver maple bark, but they may be visible when the bark is removed.)  What you describe as "very small bumps" may be, in fact, reproductive organs of the fungus.  

Symptoms
The symptoms of this disease are yellow or orange-brown to black discolored areas on the bark of the trunk and branches. Cankers, sunken dead areas of bark with black pinhead-sized speckling or pimples, may be evident. The pimples are the reproductive structures of the fungus. Under moist conditions, masses of spores may ooze out of the pimples in long,orange, coiled, thread-like spore tendrils. Reddish brown discoloration of the wood and inner bark also may be evident. Dead bark may remain attached to the tree for several years, then fall off in large pieces.