Saturday, July 11, 2020

Quiet Corner Carnivores

Drosera intermedia and a few D. rotundifolia on an old pine log in a pond in Union, Connecticut.
Much of northeastern Connecticut is underlain by thin soils and washed glacial sands and gravels, derived from nutrient-poor gneisses and other old metamorphic rocks. These poor, acidic subtrates create habitats for a variety of carnivorous plants in local bogs, seeps and ponds.

Drosera rotundifolia with freshly caught fly
We have two native sundews in the Quiet Corner. The Round-leaved Sundew, Drosera rotundifolia, is the more frequently encountered species. It usually grows in sphagnum moss in bogs or on the shores of ponds, but sometimes establishes on rotting, soggy conifer logs or sandy seeps. The Spatulate-leaved Sundew, Drosera intermedia, is most often seen in very wet, peaty mud in bogs, and usually not in living sphagnum moss, though it sometimes grows in damp sand or on fallen logs in ponds, alongside D. rotundifolia. Three other species of Drosera occur in New England, but not as far as I know in Connecticut: D. anglica and D. linearis are boreal plants restricted to the far north of the region. Drosera filiformis occured in the past on the coastal plain in southern New England, but seems to have disappeared, outside of several extant populations out on Cape Cod.

One of the largest individual plants of Drosera rotundifolia that I have ever seen, almost 20 cm across, in a small, isolated sphagnum bog back in the hills of Union, Ct. Other sundews in the area were of more typical size (5-10 cm diameter rosettes), and I suspect this one simply happened to find itself alone with no competition in a particularly favorable spot. 
Woodland sphagnum bog hosting Round-leaved Sundews in Union, Ct. Photo taken in mid-June, when the Mountain Laurels (Kalmia latifolia), state flower of Connecticut, were flowering.  


Drosera rotundifolia on a waterlogged Eastern Hemlock trunk in Union, Ct.
Sarracenia purpurea on the shore of a pond in Union, Ct. 


 Sarracenia purpurea, the Purple Pitcher Plant, is the only member of its genus that is native north of Virginia. There is an old herbarium record of one of the southern species, S. flava, growing naturalized in Mansfield, Connecticut, but have checked the site and there is no sign of anything but the native S. purpurea now. Compared to the local sundews, S. purpurea is much more exacting in its habitat requirements, only occurring in sunny sphagnum bogs or other open sites with live sphagnum moss.
Sarracenia purpurea on a floating island of sphagnum and other vegetation. The site is inaccessible except by boat or swimming; through a zoom lens from the shore the tall fruiting shoots are the only parts of the plants that are easily visible.
Utricularia radiata in a slow moving marshy stream in Eastford, Ct. Underwater shoots with bladder traps are visible to the right of the flowers.  


 Aquatic bladderworts are the most common and diverse carnivorous plants in northeastern Connecticut, with one or more of about five different Utricularia species being found in just about every lake, pond, kettle hole, sluggish stream or marsh in the area. An agricultural or ornamental pond has to be pretty badly abused before the ubiquitous U. gibba disappears. Utricularia radiata, with its aerial flowering shoots held up by distinctive star-shaped floats, seems to show up mostly in more pristine sites with cleaner water.

Another pine log community with Drosera intermedia and D. rotundifolia. See if you can spot the medium-sized snapping turtle guarding the carnivorous plants from curious waders.  

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