New York City has a lot of scaffolding. Erin Gloria Ryan posted on Twitter on September 29, 2013:
 
“The official tree of New York City is scaffolding.”
 
Ryan’s tweet was included in WNYC Digital‘s “The 19 Truest Tweets About Life in New York City” on August 1, 2014. New York City does not have an official tree, but another joke—“The official tree of New York City is sidewalk futon”—was posted by Ashley Feinberg on Twitter on May 27, 2015.
 
   
Twitter
Erin 🎶Gloria 🎶 Ryan
‏@morninggloria
The official tree of New York City is scaffolding.
10:49 AM - 29 Sep 2013
     
WNYC Digital
The 19 Truest Tweets About Life in New York City
Aug 1, 2014 · by Julie Whitaker
(...)
There is scaffolding everywhere.
Erin 🎶Gloria🎶 Ryan ✔ @morninggloria
The official tree of New York City is scaffolding.
11:49 AM - 29 Sep 2013
 
Twitter
ShauneeV
‏@sistrenista
‘The official tree of New York City is scaffolding’ LOL! http://www.wnyc.org/story/truest-tweets-about-life-new-york-city/?utm_source=local&utm_media=treatment&utm_campaign=daMost&utm_content=damostviewed … #nyc #humour
8:54 AM - 13 Aug 2014
 
Twitter
Ashley Feinberg
‏@ashleyfeinberg
The official tree of New York City is sidewalk futon
7:10 PM - 27 May 2015
   
Secret NYC
15 Times NYC Got Completely Owned On Twitter
(...)
4.
Erin 🎶Gloria🎶 Ryan ✔ @morninggloria
The official tree of New York City is scaffolding.
11:49 AM - 29 Sep 2013