Plants and Wildlife

Summer, this wonderful season of swimming, picnics, BBQ, mosquitos, posion ivy, and...Giant Hogweed? Seemingly straight out of the Jurassic age, the Giant Hogweed (Heracleum mantegazzianum) is not lightly named, living up to 25 years, with stalks reaching 15 feet tall and leaves up to 5 feet long. The plant is reminiscent of the familiar Queens Anne's lace (Daucus carota), which also falls into the carrot family (!) and whose sap has similar irritative properties. Giant Hogweed is considered a facilitative wetland plant, occurring both in wetlands and non-wetlands, generally along river beds, forest edges and other disturbed or border areas.

Beyond its impressive size, Giant Hogweed is notorious for its sap effects on skin - worse and longer lasting than than poison ivy. The sap sensitizes skin to the suns UV rays within 15 minutes, causing blisters to form within 24-72 hours, which can leave scars behind lasting months to years. The affected areas often remain sensitive to UV light, potentially leading to a recurrence of blisters years later. Even worse, if the sap if gotten in the eye, it can cause blindness.

The N.Y. Department of Health recommends that if the sap contacts skin, it be washed off with cold water immediately and either apply sunscreen or cover up the affected areas since this can prevent further reactions. The toxic reaction can begin as soon as 15 minutes after contact. If Hogweed sap gets into the eye, rinse with cold water immediately and put on sunglasses.

Giant Hogweed also is considered invasive, and quickly crowds out native species in areas it colonizes. In a dominant stand, up to 80% of incoming light is absorbed by its large leaves and flowers, shading out any species which fall under its canopy.

According to the NY DEC, the plant grows in New York, Pennsylvania, Connecticut, Ohio, Maryland, Oregon, Washington, Michigan, Virginia, Vermont, New Hampshire and Maine.

Hogweed control is difficult; it produces a prodigal amount of seeds, between 20,000 to 100,000 per year, which can remain viable for upto 7 years in the soil. Additionally, its large root can survive multiple cuttings. Control using multiple applications of herbicide over a few growing seasons is most successful. Additional info here:

Giant Hogweed in CT

Giant Hogweed Control

Hogweed Control

The Giant Hogweed Best Practice Manual, (available in multiple languages):

In my post last month about the arrival of spring peepers and wood frogs, I brushed over a portion of their lifecycle, which deserved more attention. In the Northeast USA, both spring peepers and wood frogs go through a similar hibernation cycle during the late fall to prepare the frogs to overwinter. Adaptations to freezing is not unheard of, arctic flounder have long been known to create a protein in their blood which binds to destructive ice crystals to minimize their growth, allowing them to remain mobile and thrive in the far North seas. The gene which controls the protein, was eventually incorporated into a modified tomato increase frost tolerance, but it was never commercially available due to public outcry.

The Alaskan Wood frog take a different approach to cold weather. Rather than avoiding freezing, it is embraced, but managed in such a way that tissue and organ damage is nonexistent. The frogs increase the level of glucose in their tissue in the late fall, forcing water to remain inside the cells, inhibiting ice crystal formation.

When the temperature falls below freezing, up to 60% of the frogs body is frozen solid and its respiration and heart cease for the duration. In Alaska, the frogs are frozen for most of the winter, approximately 7 months. In more temperate areas, the frog goes through the freeze and thaw cycle multiple times throughout the winter, depending on the weather. Upon the arrival of warmer weather and longer days of early spring, the frog thaws out, and starts singing!

Further Reading:

In Alaska, wood frogs freeze for seven months, thaw and hop away

Amazing Alaskan Wood Frog Freezes Solid in Winter and Comes Alive in Spring
Its spring and both gardens and wetlands are in full bloom. Out around Hempstead Lake Park on Long Island, the scent of roses accompanied me for a portion of the three mile lake loop. Hempstead Lake, the largest lake in Nassau County is largely natural, but by no means pristine; traversed by the Southern State Parkway, and surrounded by suburbia in all directions. Curious as to what created this terrific scent, I detoured onto the shoreline trails choked with poison ivy. Upon arrival, I scowled at the source of the scent, thickets of multiflora rose in bloom with its signature, one inch white flowers.

Multiflora rose, despite its wonderful scent, is an invasive species, found in both wetlands and uplands, excludes native plants from growing by crowding them out of their natural habitat. The thickets these roses bushes create can become so large and dense they have been planted roadside as a natural crash barrier.

Its cousin, the swamp rose (Rosa palustris) is found in moist soils, but can also thrive in drier soils, is also very fragrant, found with larger, pink flowers. It is an anolomy among roses, which almost as a rule, do not tolerate "wet feet".

Moving further down the trail, I was not able to find any blue flag, (Iris Versicolor), the defacto natural wetland iris found in the Northeast, but I did discover a stand of yellow iris' (Iris pseudacorus) on the north eastern shore of the lake. The yellow iris is the only yellow iris in the US and will grow in upto 1 foot of water. It is also considered invasive for the same reasons as the multiflora rose, it excludes all other plants from the area by growing large stands of plants.

Yellow Iris Wetland

Blue Flag Iris - Wetland

Multiflora Rose

Swamp Rose

Further Reading:

Invasive Yellow Iris

Swamp Rose

Subcategories

A section about Wetland plants and their unique features.

A section about Wildlife found in wetlands.

Wetlands in the News

28 April 2024