Wide Paint Brush
I'm not sure if these are standard brush sets in PS, but check and see if you have sets called "Assorted Brushes," "Dry Media Brushes," or "Thick Heavy Brushes." Some of the brushes in those sets render a natural looking brush stroke.
|AT-6 Harvard by jarud|
from Trainer aircraft
|Monarch butterflies winter roost at Pismo Beach by cjf2|
from Safety in Numbers (Nature)