Q. I've been finding odd an odd fungus (I assume) around my house.
The brown hard outer shell of a "bump" on your plants is an indicator of scale, a sucking insect on branches and leaves. They are difficult to irradicate. Horticultural oil will work, but often damages the plant. They can be picked off or dabbed with alcohol on a swab. Multiple treatments with Insecticidal soap works. Continual treatment and vigilance is needed to control them. Systemic clemical insecticides are often resorted to what all else doesn't work.