The use of the title Wellingtonia should be banned forever. Although I have every admiration and respect for the Iron Duke, the use of his name in connection with the tree is pure politics. So-called by English botanist J. Lindley in 1853, many US scientists objected to the name due to proximity of the 1812 war. Thus in 1854 the American C. Winslow proposed the name Washingtonia.
However, the purist botanical taxonomists added to the confusion by deciding that the two species were of different genera. As the coast redwood (Sequoia sempervirens) was the first of the two species to be named and described, it had to be called Sequoia.
Sequoyah was a Cherokee Indian with a German father who devised an alphabet for the Cherokee language and had no link to the trees, or to California. But he was lionised by conscience-ridden politicians of the late nineteenth century, who questioned whether policies which targeted native peoples were strictly in accordance with the sentiments embodied in the American Constitution.
Hence, both species were named Sequoia as being more aboriginal than Washintonia. But of course, there was now the generic difference, so -dendron was added to the name. This distinguished the enormous redwoods growing up in the Sierra Nevada (Sequoiadendron) from the equally colossal redwoods thriving on the coast (Sequoia.) There are now at least another six names in common usage, but the American Forest Service uses the following:
It is the former species which LCV failed to measure at Scone!
Try this method: