Americanized Dog-Strangling Vine Gardens Away From Monarch Butterflies

Summary: Americanized dog-strangling vine gardens accumulate milkweed family-like dogbane chemicals that attract monarchs but asphyxiate butterfly larvae.

dog-strangling vine's flowers and foliage: Leslie J. Mehrhoff, University of Connecticut, Bugwood.org, CC BY 3.0 United States, via Forestry Images

Americanized dog-strangling vine gardens accost native vegetation, appropriate minimal- to zero-till cultivated fields, orchards, pastures, roadsides and wastelands and assist in declining monarch butterfly populations in Canada, Mexico and the United States.

Monarch butterflies (Danaus plexippus) block off nesting niches for their eggs and larvae on herbaceous milkweeds in the Asclepiadaceae family, whose chemicals behave somewhat like dogbane's. All four stages in monarch butterfly life cycles come into contact with milkweed toxins without consequences whereas their caterpillars consume growth-inhibiting dogbane chemicals with fatal consequences. Federal, provincial and state governments describe plants native and non-native to North America as weedy for decreasing crop yields, environmental well-being, public health and species diversity. Non-native dog-strangling vine and Louise's swallowwort, not native hemp dogbane and whorled milkweed, endure weed sanctions enacted by the Connecticut, Massachusetts, New Hampshire and Vermont governments.

The Russian and Ukrainian perennial in the Apocynaceae family of dogbane herbs, shrubs, succulents and trees fits oval to elliptical cotyledons onto 1.97-inch- (5-centimeter-) long stems.

Mature dog-strangling vine gets opposite-arranged, oval to elliptical, 2.36- to 4.72-inch- (6- to 12-centimeter-) long, 0.98- to 2.76-inch- (2.5- to 7-centimeter-) wide foliage with smooth margins. It has hairy underside margins and veins on 0.19- to 0.79-inch- (5- to 20-millimeter-) long stalks, the same to four times an embryonic leaf stem's length. It includes flowering, fruiting, leafing scrambling, straight or twining, 23.62- to 98.42-inch- (60- to 250-centimeter-) long stems with woody crowns atop creeping underground stems called rhizomes.

Hairy, 0.59- to 1.97-inch- (1.5- to 5-centimeter-) long stalks juggle five- to 20-flowered inflorescences called cymes, with the oldest flowers tiptop, in Americanized dog-strangling vine gardens.

Dog-strangling vine, commonly named European swallowwort and pale swallowwort, knows May through July bloom times for brown, maroon, pink or red flowers keeping menorah-like, umbel-like patterns.

Perfect, regular flowers 0.19 to 0.28 inches (5 to 7 millimeters) across each load up two pistils, five stamens, five united petals and five united sepals. Dog-strangling vine, scientifically named Vincetoxicum rossicum (Russian poisoner), maintains 0.09- to 0.19-inch (2.5- to 5-millimeter-) long petals and 0.04- to 0.06-inch- (1- to 1.5-millimeter-) long sepals. It needs reproduction by rooted rhizomes and by seeded fruit, optimally at two dry, fruiting, smooth 1.10- to 2.76-inch- (2.8- to 7-centimeter-) long follicles per flower.

Americanized dog-strangling vine gardens offer, per square meter (10.76 square feet) flattened, light to dark brown, winged 1,330 seeds in shade and 2,100 seeds in sunlight.

White 0.79- to 1.18-inch- (2- to 3-centimeter-) long hairs project from 0.16- to 0.26-inch- (4- to 6.5-millimeter-) long, 0.09- to 0.12-inch- (2.4- to 3.1-millimeter-) wide seeds.

Germination rates for oblong to oval seeds with three- to four-year viabilities, quiver between 45 and 95 percent in the top 0.39 inch (centimeter) of soil. It responds to light, moisture and temperature variations just as mature dog-strangling vine resists sustained winter temperatures around minus 32.8 degrees Fahrenheit (minus 36 degrees Celsius). Manitoba shuns showy milkweed and spreading dogbane and, with Nova Scotia, Quebec and Mexico, common milkweed for serving livestock poisons and spreading rhizomes, seeds and viruses.

Americanized dog-strangling gardens toil least obnoxiously when their native and nonnative weedy dogbanes team up as ground covers for isolated courtyards, problem soils and research sites.

dog-strangling vines: Leslie J. Mehrhoff, University of Connecticut, Bugwood.org, CC BY 3.0 United States, via Forestry Images

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Image credits:

dog-strangling vine's flowers and foliage: Leslie J. Mehrhoff, University of Connecticut, Bugwood.org, CC BY 3.0 United States, via Forestry Images @ http://www.forestryimages.org/browse/detail.cfm?imgnum=5452251

dog-strangling vines: Leslie J. Mehrhoff, University of Connecticut, Bugwood.org, CC BY 3.0 United States, via Forestry Images @ http://www.forestryimages.org/browse/detail.cfm?imgnum=5452336

For further information:

"Asclepiadaciae Vincetoxicum rossicum (Klepow) Babar." The International Plant Names Index (IPNI) > Plant Names > Plant Name Details.
Available @ http://www.ipni.org/ipni/idPlantNameSearch.do?id=60456000-2

Barbaricz, Andrej Ivanovic. 1950. Vyznacnyk Roslyn Ukrajiny (Vyzn. Rosl. Ukr.; Viznachn. Rosl. URSR). 346.

"Cynanchum rossicum Kleopow." Tropicos® > Name Search.
Available @ http://www.tropicos.org/NameSearch.aspx

Dickinson, Richard; and Royer, France. 2014. Weeds of North America. Chicago IL; London, England: The University of Chicago Press.

Kleopow, Jurij Dmitrievič. 1929. Izvestija Kievskogo Botaničeskogo Sada 9: 67.

"Vincetoxicum rossicum (Kleopow) Babar." Tropicos® > Name Search.
Available @ http://www.tropicos.org/Name/2610480

Weakley, Alan S.; Ludwig, J. Christopher; and Townsend, John F. 2012. Flora of Virginia. Edited by Bland Crowder. Fort Worth TX: BRIT Press, Botanical Research Institute of Texas.