The Riddle of the Trees

So the NYC Street Tree Map is now available on-line and it looks amazing. Excitedly, I went to my corner of Sunset Park, Brooklyn.

Uh-oh. The trees right outside my window are Hackberries (Celtis), but they’re both mapped as Hawthorns (Crataegus). CeltisLeaves. CeltisThe really distinctive bark.

It so happened that I passed a pair of Hawthorns on the way to the subway after noting these errors. So, for comparison:CrataegusStreet-tree Crataegus. CrataegusAnd the haws of its neighbor, another of the rather varied Hawthorn genus.

But guess what? These Hawthorns were mapped as Mulberries (Morus). (Reeling.) Oy!

You know, when I saw the NYC official tree census vehicle in the neighborhood, I was struck by the fact that it had New Jersey plates. What the hell? And the corresponding pictures on the map are of winter trees, leafless — which makes for a real ID challenge in many cases.

Citizen science projects are much touted, but they generally boil down to somebody doing the grunt work of data-collecting. Having amateurs, however well-meaning, do this kind of work has its hazards. This amateur, however, has gone in and submitted corrections for these errors, but how many others are there? I found two more on the next block: two oaks are mapped as Redbuds! (Need to study further before figuring out what kind of oaks). The Ents would not be amused. I wonder how many other misidentifications there are amid the 685,781 mapped trees?

7 Responses to “The Riddle of the Trees”

  1. 1 Ms. Carol Gracie November 8, 2016 at 9:43 am

    Hi Matthew,

    I sent this post to a friend at NYBG (Daniel Atha), who is working on another project about NYC plant biodiversity that might be of interest to you. I’ll attach the recent press release.

    Daniel also worked on the Central Park plant inventory:

    Enjoyed your political commentary.



    • 2 mthew November 8, 2016 at 1:30 pm

      Hey, Carol! My friend Ken Chaya has been helping Daniel, and Regina, inventory Central. So much exciting stuff going on around here!

  2. 3 Deborah Allen November 8, 2016 at 1:24 pm

    Just looked up the trees on my block in the Bronx. One unknown and one Acer campestre. OK, it was some kind of maple anyway but with very different leaves from the one pictured on the site. Both trees are gone now with bare dirt waiting for replacement trees. It should be interesting to see how long it takes a) to get new trees, b) for them to be entered in the tree map.

  3. 5 lkewing313 November 9, 2016 at 2:00 pm

    Good to meet you in Green-Wood yesterday. (Was it really only yesterday? Seems like a lifetime ago that failing to see an evening grosbeak could register as a disappointment.)

    • 6 mthew November 9, 2016 at 3:40 pm

      It was only yesterday! And that was a lifetime ago. What an effing disaster. I have such a head cold now and that’s on top of the horrible news. I did manage to see the Chat and a mouse-like Winter Wren at Trinity Church, though. Very Chat and Mouse…

  1. 1 Hackberry | Backyard and Beyond Trackback on June 15, 2017 at 7:01 am

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