As posted above, name is not the only criteria. Where YOUR family lived in
Scotland is the key. The Comyn name was banned in the fallout of a dispute
over succession to the crown. The Lendrum name is a place name adopted by one of the most directly affected sons. Others followed suit, reasons could vary by family. It is said that most with the name in this country can be traced to two brothers who came to VA from Scotland.

Have sent a PM which may or may not be relevant to your situation. Only
your genealogy can make a definitive statement. In this country, wear what you choose, join the clan society or not, or petition the clan chief directly.
If none, you're on your own. I did not see your name on the "accepted"
names list, nor is it on the list used by the Clan Cumming Society of the US.
The clan appears to be armigerous.

The Tartan Police will not appear at your door, they being in bit of a bind with Homeland Security over statements taken out of context to be terroristic in nature, and by the time that's resolved you'll have your genealogy well in hand. In the meantime, wear what your heart calls you to,
being prepared to have discussions with those of an officious nature.
Wear it well, with respect,wiyh knowledge of the tartan, with joy, and with a good story about how it came be your choice. Do take a look at the Society page.

HAVE FUN!!