You have mold that should be removed.
Black mold on attic rafters.
The surfaces that black mold will grow on in your attic in the attic the most common places to find black mold are the places where water is likely to be a problem.
On the east side only there is black mold for the first 6 up the slope.
Black mold can also grow behind the walls or attic ceilings completely undetected until the occupants smell the presence or experience health problems.
Leak from roof may create drips that further dampen your attic making it more susceptible to mold.
At the south end of the roof the ridge changes direction causing an overlay condition.
The black mold is on the first 3 truss panels.
Attic feels excessively hot or stuffy attics should feel breezy if they are properly ventilated.
Skips a few trusses and reappears on the next panel or two.
Add bad ventilation and high humidity level and you get perfect breeding grounds for black mold.
Walls that are improperly insulated may develop mold because they will absorb moisture from outside.