The tree in question is a Magnolia tree.  Thank you Nancy Owens

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Dear Nancy,

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YOUR QUESTION #0147466:

Disease on tree

The disease on this tree , has bumps on the branches and black oil on the leaves . The oil is dripping on the ground and on my Lilly turf.

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Hello, 
Your magnolia tree has either magnolia or tuliptree scale. This is a soft-scale insect that can be tricky to control. Th black deposits on the plants below the tree is actually a sooty mold that is populating the honeydew (or excrement) from the scale. 
Soft scale use their piercing sucking mouthparts to penetrate the bark and suck sap from the plant. The sap has so much excess sugar that the insects secrete it in the form of honeydew. The honeydew itself is a clear liquid, but when it collects on surfaces below the scale, it is the perfect habitat for sooty mold to form. This can occur on lower leaves and branches of the infected plant as well as other plants or structures under the infected plant.

Both magnolia and tuliptree scale are native insects and therefore have numerous natural predators. A scale infestation will not cause long-term damage to a healthy mature tree, however a particularly heavy infestation on a stressed or young tree may, over time, cause the tree to decline. 
The bumps on your tree are the females and as the summer progresses they get larger as they produce eggs inside their soft helmet-like covering. The eggs hatch directly from the covering making it look like the scale is giving birth to live young. These crawlers are the vulnerable stage of the insect. Using any type of pesticide on the adult insects will have no affect as the pesticide will not penetrate their helmet covering.

The sooty mold is a general nuisance and unsightly but will not cause long-term damage to the plants it appears on.

If you are able to reach many of the infested branches, you can use a dish scrubber to scrape the scale off of the branches before the eggs hatch and significantly reduce the population. Egg hatch typically occurs in late July to early August so I would recommend using this method soon if possible.

This Buckeye Yard and Garden Line (BYGL) article from Ohio State extension has much more detailed information about magnolia and tuliptree scale, including photos and information on potential predators that can help control the populations. 

If your magnolia tree is healthy and otherwise not under stress, eliminating as many female scale as possible before egg hatch may be all that is needed to protect your tree. It is quite common to see populations rise and fall from year to year without any intervention.