14 April 2026
Most trees in western Pennsylvania have trunks that taper gradually from the ground to the first large branches. Some have a few lumpy above-ground roots but our tree trunks generally look like the white oak at left below.
Buttress roots — the vertical flanges on the tree at top — are so unusual in Pittsburgh that I take photos of them. In this case it’s an American elm in Schenley Park.
In some habitats buttress roots are normal, such as on bald cypresses in swamps …
… and tropical trees like this one in Panama.
Why do tropical trees have such enormous buttress roots? Bill Sutherland answers that question.
p.s. The name for these root structures comes from the buttresses, best seen in Gothic architecture, that hold up tall heavy walls and high vaulted ceilings. The walls would collapse outward without the added support.
The buttresses on Heinz Chapel are so beautiful that we take them for granted. There are at least three in this photo.
