When a plant that should be compact or shrubby gets too lanky with exposed lower stems, it is described as ‘leggy’. We do not hear much about plants that develop ‘knees’. Perhaps that is because there is only one species that does so. That one species happens to be very rare here. If there are other specie that develop knees, I do not know what they are.
‘Knees’ are weird appendages that grow upward like stalagmites from the roots of bald cypress Taxodium distichum, particularly where the trees grow wild in swampy conditions. Knees can get quite tall. One of our professors used to tell us that they could do some serious damage to a canoe. Perhaps knees are why bald cypress is locally unpopular in landscapes.
However, I happened to notice that bald cypress is a common street tree in downtown Oklahoma City. Just like most other street trees, they are installed into small tree wells, but otherwise surrounded by pavement. They were remarkably healthy and well structured specimens that were too young to have damaged the pavement. Yet, I could not help but wonder what they will do as they mature. Even before the trunks grow as big around as the small tree wells that they are in, what would happen if knees develop?
There happens to be not one, but two bald cypress at work. The smaller is alongside a small stream. The larger is adjacent to a lawn where the soil is seemingly dry on the surface, but quite soggy just below the surface. This larger specimen is already developing distended burls that seem to be rudimentary knees. Although there is no pavement to break, the tree happens to be shading a picnic area where knees, if they develop, would be quite an obtrusive problem.