The line between whether a plant is a "tree" or a "shrub" is sometimes very thin and quite blurry! We use the following criteria to decide which type applies to a certain plant:
Cephalotaxus harringtonia 'Fritz Huber'
Cephalotaxus harringtonia 'Gold Rush' Pick-up ONLY
Cornus florida 'Suwannee Squat'
Illicium x 'Scorpio'
Magnolia x loebneri 'Donna'