Category: Drosera

Threadleaf Sundews on the Pondshore

The serenity of a fresh water pond, on a late Spring day. For us humans, it may seem a tranquil moment of bliss, but for the inhabitants it is a constant struggle for survival. The ecosystem goes on as it has for millennia, a food chain of energy extending through all manner of pond denizens, great and small, which eke out their existence in this symphony of life. Creatures such as the Great Blue Heron (Ardea herodias), Snapping Turtle (Chelydra serpentina), American Bull Frog (Rana catesbeiana), Chain Pickerel (Esox niger), Freshwater Leech (Macrobdella decora), and various Dragonfly and Damselfly species (Odonata), are all residents of this pond. All with voracious appetites for their prey, where even the plants can be dangerous predators in this community. It is these carnivorous plants that are of special interest, especially the threadleaf sundew (Drosera filiformis). Of all the ponds on Long Island, this location contains one of the greatest populations of this unusual carnivorous plant.

In the first photograph, we see a prey capture of what looks to be a Pine Barrens Bluet (Enallagma recurvatum) by Drosera filiformis. Though it may struggle, there is little chance that it will ever escape its fate of being consumed by the plant. The second photograph is a cluster of plants, they appear to have divided upon themselves into this mass, creating a formidable wall of death for any insect that may chance upon it.  For the third photograph, we see a pleasant portrait of a pair of plants along the sunny pond shore where they live, and the fourth photograph shows Drosera filiformis in their sandy habitat with other interesting plants surrounding them, such as the spoonleaf sundew (Drosera intermedia) and the Meadow Beauty (Rhexia virginica). The final photograph is a view of this coastal plains pond habitat where these plants grow. Surrounded by upland pitch pine-oak forest with understory shrubs, the gently sloping shores of the pond have sandy, nutrient-poor soils, and contain a great diversity of plant life. Some of which have adapted to deviously lure, trap and consume their prey. Another one of the many predators in this complex cycle of life and death, that of which takes place among the serenity of this freshwater pond, on a late Spring day.


Bog Things


Interesting creatures are often seen within the fantastic habitats of carnivorous plants across Long Island. Some can be somewhat common, while others rare. But all are beautiful in their own ways, and are always wonderful to discover. Visits to the Sphagnum bogs and ponds near the Peconic River were where these photographs were taken, and these are just a few of the interesting subjects that were observed on those summer days. In the first photograph, a cluster of traps of the spoonleaf sundew, Drosera intermedia, with brilliant red coloration is seen. The second photograph, we have a detail of these traps sparkling in the mid-day sun, showing the particular shape of the traps of this species. For the third photograph, a detailed look of a trap from the hybrid sundew, Drosera x belezeana (Drosera rotundifolia x intermedia). Known from other parts of the world, this hybrid was recorded for the first time in New York, by the author in the summer of 2012. This particular trap is a great example of the blending of characteristics between the parent species. For quick observation, the trap appears much like that of Drosera rotundifolia, yet is nowhere as wide, and a little more elongated, inheriting some traits from Drosera intermedia.

Onto the fourth photograph, there is a trap from the purple pitcher plant, Sarracenia purpurea, springing forth from its mossy habitat of the Sphagnum bog.  The fifth photograph, is a flower of the Broadleaf Arrowhead, Sagittaria latifolia, which often grows near carnivorous plants in the wetter parts of the habitats. Sometimes known as the Duck Potato, which is strange, because ducks rarely eat the tubers of this plant. And for the final photograph, we see a female Green Frog, Lithobates clamitans, sitting on the edge of a coastal plains pond. The frog was very cooperative, allowing for close-up photographs with a 50mm lens coupled with a set of macro tubes. Was she remaining so perfectly still hoping to go unnoticed by a potential predator? Or was she gracefully posing for the photography session, basking in the adoration and recognition of her glorious beauty?  I asked, but she only replied “ribbit”.

Sundews in the Sand Dunes


Drosera filiformis, or the threadleaf sundew, tend to grow in sandy and wet areas on Long Island, usually near or around coastal plains ponds. They also surprisingly grow among the sand dunes of the south fork of Long Island. Some of these dunes can reach 80 feet high, and shift with the winds, marching steadily across the landscape. In these dunes, there are swales, and there is one that reaches down to the ground water table. This keeps the sandy soil consistently wet with fresh water, and cranberry, Vaccinium macrocarpon, and pitch pine trees, Pinus rigida, grow throughout this swale. Other interesting plants grow here as well, such as the bog orchids Rose Pogonia, Pogonia ophioglossoides, and the Grass Pink, Calopogon tuberosus. Then there are the carnivorous plants, the spoonleaf sundew Drosera intermedia, and of the most interest here, the threadleaf sundew, Drosera filiformis.
In the first photograph, we see a swath of Drosera filiformis, growing in nearly pure sand and exposed to continuous sunlight throughout the day. The second photograph shows a closer look at this population, and the sandy soil where it grows. The color of the plants appear to be a curious orange color, where Drosera filiformis are known as mostly green, or completely red, in the case of certain populations in Florida. For the third photograph, we have a detailed view of an individual plant from this population. With closer inspection, we see that its leaves are still green, but very much a yellow-green color. Perhaps because of the long-term continuous exposure to strong sunlight, the green color of the leaves of these plants, have shifted to become more yellow. The trapping tentacles are the typical red color, and when seen from an average viewing distance, it seems that the yellow tinge of the leaves, combined with the red tentacles, give the plants the pleasant orange hue we see here. This is observed at one specific spot in this dune swale location, the other Drosera filiformis nearby, being more typical in character. Other locations on Long Island can have plants with an orange tinge to their hue when exposed to strong sunlight, just never quite as brilliant as these particular plants in this little swath in the great dune swale.
The fourth photograph shows the flower of Drosera filiformis from this population, and the final photograph shows the flowers being pollinated by a bee-mimic hoverfly, perhaps a species of Sphaerophoria. The carnivorous traps seem precariously close to their flowers, yet when the hoverfly was observed, it went directly from flower to flower with focused purpose, and no distraction. There are other nearby locations where Drosera filiformis grow within sand dune swales, although this is the most brilliant of them all. Strange as it may seem, that surrounded by dry sand, with no visible fresh water, and with the salt-water of the sea mere hundreds of yards away, plants that are normally found around ponds can flourish with such great vigor and numbers. Though here they are, another wonderful surprise in the unusual and bizarre world of carnivorous plants.

Threadleaf sundews in the sunshine


The graceful and wicked Drosera filiformis, commonly known as the threadleaf sundew. These plants are growing naturally along the gently sloping, sandy shoreline of a coastal plains pond on the south fork of Long Island, NY. Seen in the photos are details of the traps of the plant, a profile of one of the plants with seed pods developing on its flower stalks, the open habitat where they grow, and a prey capture of the spider wasp, Episyron biguttatus.
This location is one of Long Island’s greatest populations for this plant, and it is thanks to the local conservation groups that this land was not developed. Without their efforts, it is most certain that the habit where the plants grow would have been plowed over for waterfront housing, and manicured green lawns. Forever removing the ecosystem where these, and many other rare and unusual plants grow, with the animals that coexist with them. Photographs are from the early Summer season of 2013.