Williamson Pond, Columbia
Williamson Pond Species Map
(1.2 MB, .pdf format*)

Transect Data (17 KB, .pdf format) | Water Data

   Williamson Pond is a 0.1 acre privately owned pond located in Columbia, CT.   It was surveyed in August of 2008 based on a tip that it might contain the invasive species Nymphoides peltata. The last  documented report of this plant in Connecticut was in 1900.    

   The invasive species, Nymphoides peltata was found along with Myriophyllum aquaticum and six native plantspecies.Nymphoides peltata covered over 95% of the pond and was extremely dense. Myriophyllum aquaticum was very sparse and only occurred on the south-eastern shoreline. This is the furthest north  Myriophyllum aquaticum has been found by CAES IAPP and indicates it can survive the winters in most of the State.  Ludwigia palustris was found bordering the edges around the pond and Potamogeton bicupulatus.

Find Common Plant Names

(65 KB, .pdf format*)

Species recorded in our 2008 survey of Williamson Pond. Click on plant to view herbarium mount. (invasive species in bold)

Alisma sp.

Eleocharis sp.

Ludwigia palustris

Myriophyllum aquaticum

Nymphaea odorata

Nymphoides peltata

Polygonum hydropiperoides 

Potamogeton bicupulatus

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