What's growing in some neglected tree planters in Morningside Heights

At the end of my block on the southeast corner of Broadway and 112th Street there are four tree planters that have been left neglected. Three no longer have trees in them and one has a youthful tree. All four have been taken over by whatever plants have been able to make progress on this abandoned land - some 3 square meters each. The four have a quite different collection of plants.

I wondered how exotic the plants would be. After all, these are located right by a ton of restaurants, food stores and take out places and could conceivably be accidental receptacles for all sorts of seeds. Maybe a tomato plant? However there seems little or nothing that might have originated from some discarded food stuffs or packaging.

I identified the plants with iNaturalist and some googling

The most southern planter has been essentially taken over by just two plants. There is a black locust on the east side and a huge black nightshade, full of berries, on the west side. Two horseweeds are also there.

In second most southern of the four planters I have identified the following plants:
Spindle
Eastern black nightshade
Giant foxtail
Fragrant bedstraw
Woodsorrel (a community member suggested this was upright yellow woodsorrel)
Fringed loosestrife (a community member disagreed that that was correct!)

In the planter to the north it is totally different. This one has been taken over by a giant bush of white sweetclover with nothing else. The bush is about 5 feet high and probably ten feet in circumference!

In the most northern of the planters there is a quite different plant community. I identified - two were corrected due to input from another iNaturalist person (thanks!):
Robin's plantain
Common dandelion
Common wrinkle-leaved goldenrod
Horseweed
Siberian elm
Upright yellow wood sorrel
Hedge bedstraw

The oddity here is a baby Siberian elm trying to make a go of it. These grow in Riverside Park which is just one block away so it is not too surprising to find this here.

The collected assemblage is a mix of native (e.g. wood sorrel, horse weed, black locust) and introduced (e.g. foxtail, white sweetclover, spindle) plants, about equally split. Most are considered troublesome weeds.

So, why did the four adjacent and near equally neglected planters end up with such different plant communities? Nothing here seems to be related to seeds spread by people from discarded food. There seems limited overlap between the planters. I wonder how it is the communities develop differently.

Posted on August 16, 2020 01:22 PM by rseager