The two trees with great, spreading branches are BUR OAKS. Their name comes from the bur-like appearance of their acorn caps.  This is the tree the pioneers most often encountered in prairie groves (also known as oak openings), as, according to Aldo Leopold, "Bur oaks were the shock troops sent by the invading forest to storm the prairie; fire is what they had to fight."   And they do a good job at it, too.  As you can see here and elsewhere throughout Severson Dells, these old, `tough-skinned' trees have been resisting the Forest Preserve's prescribed burns for years and the prairie's naturally occurring fires for many more years before that.

Out of respect for these majestic, mangled oaks let's sing a song about bur oaks and other members of the oak family.  The hand motions for the song are in parenthesis.  Please sing this to the tune of "Row, Row, Row Your Boat:"

Know, know, know your oaks  (tap your temple with your finger)
This is how they grow –
Red oaks (hands straight up in the air),
White oaks (hands still up high, but moved out at your sides a bit),
Pin oaks (hands straight out at your sides),
Bur oaks (hands twisted around in strange, uncomfortable positions),
And acorns down below, hey!