One of our favorite evergreen trees is the little-known, Trochodendron aralioides. I first met the wheel tree at the JC Raulston Arboretum back in the 1980s, quickly falling in love with the fascinating foliage, which is arranged at the branch tips, like spokes on a wheel. As the curator of the Arboretum’s Lath House, I was able to watch it regularly, being particularly fascinated at its incredibly slow growth rate. It was 2008, before I got to meet it in the wilds of Taiwan (lower photo). I had no idea the trees would get this massive, but based on their growth rate, these trees were most like several hundred years old. Our 27 year old garden specimens are now 12′ tall x 12′ wide.
The other oddity is the crazy flowers, that look nothing like any other plant on the planet.
Trochodendron is a monotypic genus, meaning that all other species in the genus are now extinct. Interestingly, Trochodendron was originally only a North American native genus, which eventually spread across the Bering land bridge to Japan and Taiwan, before going extinct in North America. Now, despite the movement to restore native plants to their “original” locations, Trochodendron is still a stranger in its own homeland, since most self-described native plant purists only define native as what existed when Christopher Columbus arrived.
The genus is so odd, that their has been little consensus in which plant family this belongs. It was originally a member of the magnolia family (Magnoliaceae), before being relegated to the Winteraceae family, then moving on to the Ternstroemiaceae family, followed by the Tetracentraceae. Taxonomists finally threw in the towel and created its own family, Trochodendraceae, which it now shares with the genus, Tetracentron. Can you imagine what kind of behaviorial issue arise from getting booted from your native home as well as four different families. We think Trochodendron deserves some love, so perhaps growing one in you own garden would be a nice way to start the healing process and let them know that they are welcomed back to North America.
I first saw this plant at the Cox Arboretum. Tom convinced me to add one to my garden, I was pleased to have found one for sale. I am surprised that I don’t see this in more gardens and collections.
Here’s ours a couple weeks ago. Planted about 10 years ago in Vancouver Washington
I have a very small Trochodendron tree growing in my yard in Chapel Hill, but I never realized it was a North American native. I’ll now be able to show it off without embarrassment to some of my “native plant only” neighbors!!
Fascinating commentary. (Please note the orthography of the specific epithet, aralioides, as in looking like Aralia.) TLH