LONDON — For some people, Christmas is all about carols, presents, Santa Claus and his reindeer.

Not for Trevor Smith, for whom the highlight of the festive season is a tall, woody perennial fir that is dispatched every year from Norway to Britain: the Christmas tree in Trafalgar Square. This year, however, the tree is not a sight for sore eyes.

Just two years after Romans mocked their Christmas tree, nicknaming it Spelacchio — Mangy — it’s now Londoners’ turn to unite in their shared disappointment in the sparse spruce .

“I come every year, and this one is quite bare,” Mr. Smith, 73, said on Thursday, gazing at the thin, 79-foot tree standing at the foot of the National Gallery in Central London.

Like a child excitedly unwrapping presents on Christmas morning, Mr. Smith travels every year from his house near Heathrow International Airport to Trafalgar Square after the tree is erected just to get a glimpse.