Americanized Toadflax Gardens: Toxins for Poultry, Viruses for Tobacco

Summary: Americanized toadflax gardens contain toxic, weedy relatives in courtyards, railway grades, roadsides and wastelands away from crops, livestock and vegetables.

toadflax (Linaria vulgaris) in Superior National Forest, Arrowhead Region, northeastern Minnesota; Oct. 19, 2010: Superior National Forest, CC BY 2.0, via Flickr

Americanized toadflax gardens appear as far north as Fairbanks, Alaska, in the United States and Fort Smith, Northwest Territories, in Canada within 150 years of introductions into North America as mid-19th-century ornamentals.

Toadflax brings creeping rhizomes and prolific seeds to minimal- and zero-till farmlands, mosaic virus to tobacco croplands and toxins to cattle and banishes grasses from rangelands. Land invasions confer weed status upon Asian marshweed, common plantain, Dalmatian toadflax, dwarf snapdragon, flaxseed plantain, ribgrass and toadflax, non-native plantain relatives in the Plantaginaceae family. Alberta, British Columbia, Manitoba and Saskatchewan provincial and Idaho, Montana, Nevada, New Mexico, Oregon, South Dakota, Washington and Wyoming state legislation designate toadflax an unwelcome weed.

The Canadian and the Mexican governments expose the European herbaceous perennial, described by Philip Miller (1691-Dec. 18, 1771), English botanist of Scottish descent, to federal sanctions.

The seedling stage fits pointed tips onto hairless, 0.05- to 0.39-inch- (1.3- to 10-millimeter-) long, 0.04- to 0.16-inch- (1- to 4-millimeter-) wide embryonic leaves called cotyledons.

First-stage foliage gets opposite-arranged, oval-shaped leaves while root buds, 90 to 100 by first growing season end, grow shoots within three weeks of germinated seed emergence. Mature, 11.82- to 51.18-inch- (30- to 130-centimeter-) tall toadflax has hairless stems with countless buds and with crowded, opposite-looking but alternate-arranged, pale green, short-stalked, smooth-margined foliage. Maturity increases foliage to 0.79- to 3.94-inch (2- to 10-centimeter) lengths and 0.04- to 0.19-inch (1- to 5-millimeter) widths and soil coverage to 3.28-foot (1-meter) diameters.

Similar-looking, weedy Dalmatian toadflax juggles 1.18- to 1.58-inch- (3- to 4-centimeter-) long flowers, oval to lance-shaped leaves and 3.28-foot- (1-meter-) tall stems in Americanized toadflax gardens.

Dense, terminal inflorescences called racemes keep July to October bloom times for perfect, orange-throated, snapdragon-like, yellow flowers on 1.97-inch- (5-centimeter-) long stalklets along central main stalks.

Every flower lodges one pistil, four stamens, five united petals with 0.79- to 1.18-inch- (2- to 3-centimeter-) long projecting spurs and five united sepals called calyces. The 0.79- to 1.38-inch (2- to 3.5-centimeter-) long flowers make way for oval to egg-shaped, 0.32- to 0.47-inch- (8- to 12-millimeter-) long, three- to 110-seeded capsules. All of one toadflax's dry, explosive, fruiting capsules optimally nurture 8,700 dull black, flattened, oval seeds, each 0.06 to 0.08 inches (1.5 to 2 millimeters) across.

Underground stems called rhizomes whose 3.94-inch (10-centimeter-) long fragments occupy colonies 6.56 feet (2 meters) in diameter and seeds offer Americanized toadflax gardens two reproduction means.

Toadflax, commonly called butter-and-eggs, eggs-and-bacon, flaxweed, impudent lawyer, Jacob's ladder, perennial snapdragon, rabbit flower, ramsted, wild snapdragon and yellow toadflax, produces seeds with 13-year in-soil viabilities.

Natural, wildlife and wind dispersal to locations from the surface down 1.18 inches (3 centimeters) quickens germination of toadflax, scientifically named Linaria vulgaris (flax-like [leaf], common). Toadflax-like rhizomes, seeds and toxins result in no toadflax-like restrictions on related Grecian foxglove of southern Europe, buckthorn plantain of Europe and hoary plantain of Eurasia. Federal, provincial and state governments serve weed sanctions against native large-bracted plantain, but not against native common speedwell, despite both sharing toadflax-like rhizomes, seeds and toxins.

Toxic, weedy Americanized toadflax gardens torment crops, livestock and vegetables least in barren, compacted, disturbed courtyards, railroads, roadsides and wastelands away from croplands, gardens and rangelands.

closeup of toadflax's orange and yellow flowers; National Cycle Route 12, Stevenage, Hertfordshire, East of England; Sept. 27, 2009; Peter O'Connor aka anemoneprojectors, CC BY SA 2.0, via Flickr

Acknowledgment

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

Image credits:

toadflax (Linaria vulgaris), also known as butter-and-eggs, in Superior National Forest, Arrowhead Region, northeastern Minnesota; Oct. 19, 2010: Superior National Forest, CC BY 2.0, via Flickr @ https://www.flickr.com/photos/superiornationalforest/5097904934/

closeup of toadflax's orange and yellow flowers; National Cycle Route 12, Stevenage, Hertfordshire, East of England; Sept. 27, 2009; Peter O'Connor aka anemoneprojectors, CC BY SA 2.0, via Flickr @ https://www.flickr.com/photos/anemoneprojectors/3959820419/

For further information:

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

"Linaria vulgaris Mill." Tropicos® > Name Search.
Available @ http://www.tropicos.org/Name/29207754

Miller, Philip. 1768. "1. Linaria (Vulgaris)." The Gardener's Dictionary, vol. 2: 320 (Lim-Lin). Eighth edition. London, England: John & Francis Rivington.
Available via Biodiversity Heritage Library @ http://biodiversitylibrary.org/page/51493717

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.