Sept. 1, 2016, Annular Eclipse Favors Central Africa and Madagascar

Summary: Occurring as 2016’s second and last solar eclipse, the Sept. 1, 2016, annular eclipse is primarily viewable over Central Africa and Madagascar.

details of Sept. 1, 2016, annular eclipse; numbers on blue lines indicate eclipse magnitudes, i.e., fractions of the sun's diameter occulted (Latin: occulto, "cover, hide") by the moon: Fred Espenak/NASA Goddard Space Flight Center (GSFC), Public Domain, via NASA Eclipse Web Site

The Sept. 1, 2016, annular eclipse traces a path over the land masses of Central Africa and Madagascar and occurs as the second and last solar eclipse of 2016.

Partial eclipses precede and follow Thursday’s annular eclipse. The viewing area of the partial eclipse encompasses three oceans: Atlantic, Indian, Southern. Thursday’s annular eclipse is visible as a partial eclipse over four continents: most of Africa, much of the western Arabian Peninsula in western Asia, a portion of northeastern Antarctica, the western slice of the state of Western Australia. The partial eclipse is also viewable over Southern Sumatra and most of Java in the Indonesian archipelago.

The second and last solar eclipse of 2016 begins as a partial eclipse at 06:13:08.3 Coordinated Universal Time (UTC). The start of annularity takes place at 07:17:49.6 UTC. The Sept. 1, 2016, annular eclipse ends at 10:55:53.7 UTC. The partial eclipse ends at noon, 12:00:40.5 UTC.

The complete ecliptic event, beginning with a partial eclipse and ending with a partial eclipse, accounts for about 5.7 hours. The annular eclipse completes its path in about 3.6 hours.

On his map of the Sept. 1, 2016, annular eclipse, NASA astrophysicist Fred Espenak (“Mr. Eclipse”) indicates the path of annularity with double red lines. The path of annularity ribbons from the South Atlantic Ocean eastward across Central Africa and northern Madagascar and ending in the South Indian Ocean west of Australia.

EarthSky Tonight’s lead writer, Bruce McClure, notes that the path of annularity extends across approximately 13,400 kilometers (8,330 miles). Fred Espenak places the path width at 99.7 kilometers (61.95 miles) at the point of greatest eclipse, i.e., the instance of closest passage of the axis of the lunar shadow cone to Earth’s center.

Fred Espenak places the time of the greatest eclipse at 09:06:53.9 UTC. Greatest eclipse designates the instant of closest passage of the axis of the lunar shadow cone to Earth's center. The greatest eclipse occurs over southwestern Tanzania in East Africa. The lucky location is sited in eastern Tunduru District in southeastern Ruvuma Region. The geographic coordinates are 10 degrees 40.9 minutes south latitude, 37 degrees 45.7 minutes east longitude.

The greatest duration of the annular eclipse happens at 09:05:09.7 UTC. Greatest duration lasts for 3 minutes 5.6 seconds. A site in the eastern Tunduru District, northwest of the greatest eclipse’s occurrence, claims greatest duration. Geographic coordinates for the location are 10 degrees 26 minutes south latitude, 37 degrees 21 minutes east longitude.

An annular eclipse is a solar eclipse in which the sun surrounds the entire silhouetted lunar disk with an excruciatingly bright annulus (Latin: “little ring”). The moon’s distance is too far from Earth for complete coverage of the sun.

In an annular eclipse, the moon casts its antumbral shadow onto Earth. The antumbra (Latin: ante, “before, in front of” + umbra, “shadow”) is one of a shadow’s three distinctive parts. A shadow’s darkest innermost part is termed the umbra. Total solar eclipses are associated with umbral shadows.

Penumbra (Latin: paene “almost”) refers to the shadow’s faint, outer flanks. Partial solar eclipses are associated with penumbral shadows.

Antumbra applies to the faint, outer part extending lengthwise from the umbra. Annular eclipses are associated with antumbral shadows.

EarthSky Tonight’s lead writer, Bruce McClure, notes that in the 21st century, which runs from Jan. 1, 2001, to Dec. 31, 2100, annular solar eclipses are in second place, with 72 occurrences. First-place partial solar eclipses account for 72 of the century’s 224 solar eclipses. In third place, total solar eclipses make 68 appearances. Rare hybrid eclipses, which are partly annular and partly total, claim 7 events.

The most recent occurrence of an annular eclipse, prior to Thursday’s appearance, took place Tuesday, April 29, 2014. The next annular eclipse takes place Sunday, Feb. 26, 2017.

Animated GIF of Thursday, Sept. 1, 2016, annular eclipse shows path of annularity and path of partiality: A.T. Sinclair/NASA, Public Domain, via Wikimedia Commons

Acknowledgment

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

Image credits:

Path of annular eclipse, Sept. 1, 2016: Fred Espenak/NASA Goddard Space Flight Center, Public Domain, via Wikimedia Commons @ https://commons.wikimedia.org/wiki/File:SE2016Sep01A.png

Animation of path of annular eclipse, Sept. 1, 2016: A.T. Sinclair/NASA Eclipse Web Site, Public Domain, via Wikimedia Commons @ https://commons.wikimedia.org/wiki/File:SE2016Sep01A.GIF

For further information:

“Annular Solar Eclipse of 2016 Sep 01.” NASA Eclipse Web Site.
Available @ http://eclipse.gsfc.nasa.gov/SEgoogle/SEgoogle2001/SE2016Sep01Agoogle.html

Astronomical Society Southern Africa. “Solar Eclipse: 1 September 2016.” YouTube. Scheduled for Sept. 1, 2016.
Available @ https://www.youtube.com/watch?v=xebDaX1PJF0

Espenak, Fred. “Glossary of Solar Eclipse Terms.” NASA Eclipse Web Site > Solar Eclipses.
Available @ http://eclipse.gsfc.nasa.gov/SEhelp/SEglossary.html#annular

Espenak, Fred. “Google Maps and Solar Eclipse Paths: 2001-2020.” NASA Eclipse Web Site > Solar Eclipses.
Available @ http://eclipse.gsfc.nasa.gov/SEgoogle/SEgoogle2001.html

Koehn, Larry. “Annular Eclipse of the Sun Over Africa On September 1, 2016.” YouTube. April 28, 2016.
Available @ https://www.youtube.com/watch?v=VWxRj2fhH4M

Kramer, Bill. "Eclipse Chaser Terminology." Eclipse Chasers. Last update April 17, 2015.
Available @ https://www.eclipse-chasers.com/php/tseAssist.php?SA=1#F

Marriner, Derdriu. “2016 Eclipse Lineup Features Two Lunar and Two Solar Eclipses.” Earth and Space News. Tuesday, March 8, 2016.
Available @ https://earth-and-space-news.blogspot.com/2016/03/2016-eclipse-lineup-features-two-lunar.html

Marriner, Derdriu. “Alaska Airlines Flight 870 Adjusted for Solar Eclipse Chasers.” Earth and Space News. Tuesday, March 8, 2016.
Available @ https://earth-and-space-news.blogspot.com/2016/03/alaska-airlines-flight-870-adjusted-for.html

Marriner, Derdriu. “March 8 to 9, 2016, Total Solar Eclipse Path Crosses Indonesia.” Earth and Space News. Friday, March 4, 2016.
Available @ https://earth-and-space-news.blogspot.com/2016/03/march-8-to-9-2016-total-solar-eclipse.html

McClure, Bruce. “African solar eclipse on September 1.” EarthSky > Tonight. Aug. 31, 2016.
Available @ http://earthsky.org/tonight/african-solar-eclipse-on-september-1-2016

“September 1, 2016 – Annular Solar Eclipse.” Time And Date > Sun & Moon > Eclipses.
Available @ http://www.timeanddate.com/eclipse/solar/2016-september-1

“Tanzania: Administrative Division.” City Population > Africa.
Available @ http://www.citypopulation.de/php/tanzania-admin.php

“What Are Solar Eclipses?” Time And Date > Sun & Moon > Eclipses > Frequency.
Available @ http://www.timeanddate.com/eclipse/solar-eclipse-frequency.html

“What is an Annular Solar Eclipse?” Time And Date > Sun & Moon > Eclipses.
Available @ http://www.timeanddate.com/eclipse/annular-solar-eclipse.html

Canada Goldenrod Solidago canadensis Has Therapeutic Qualities

Summary: New World native perennial Canada Goldenrod (Solidago canadensis), upholds the reputation of many goldenrod species as promoters of well-being.

Canada goldenrod, Teton County, northwestern Wyoming: Matt Lavin, CC BY SA 2.0, via Wikimedia Commons

As a species in the Solidago plant genus, Canada goldenrod (Solidago canadensis) continues the goldenrod reputation for promoting well-being in folk and Native American medicinal remedies. The genus name, Solidago (Latin: solido, "to heal, to make heal”), recognizes the therapeutic qualities of many goldenrod species.

Five varieties of Solidago canadensis have been recognized: canadensis, gilvocanescens, hargeri, salebrosa and scabra. The scabra variety is synonymous with Solidago altissima. Originally considered as a single species, scabra was reclassified as a variety of Canada goldenrod. Evolutionary ecology biologists Warren G. Abrahamson of Lewisburg, Pennsylvania’s Bucknell University and Arthur Edward Weis of the University of California, Irvine, find that the scabra variety is morphologically closest to the gilvocanescens variety.

The Flora of North America, an in-print and online compendium focusing on the more than 20,000 native and naturalized species found in North America north of Mexico, considers the scabra variety as a single species under its original scientific name, Solidago altissima. Early research in 1997 by Abrahamson and Weis and recent reporting in 2007 by Timothy P. Craig and Joanne K. Itami of the University of Minnesota at Duluth and John D. Horner of Texas Christian University reveal that the parasitic gall-forming insect Eurosta solidaginis, known commonly as the Goldenrod Gall Fly, only injects eggs into the stems of gilvocanescens and scabra varieties of Canadian goldenrod. Formation of ball-shaped, abnormal outgrowths, called galls, confirms the presence of the parasite’s larvae. The other three varieties of Canada goldenrod do not serve as habitats or food sources for gall-forming insects.

Native American ethnobotany is replete with remedies based upon Canada goldenrod.

The Iroquois of northeastern North America find numerous healing applications for Canada goldenrod. An analgesic infusion of flowers and roots treats side pains. A compound infusion of roots serves as an emetic aid to induce vomiting. A compound infusion of tubers, or rhizomes, is a pediatric sedative for babies who make sudden starts while sleeping.

Known to colonists as the Fox tribe, the Meskwaki (Meshkwahkihaki, “the Red Earth people”) of the Great Lakes region apply Canada goldenrod as a psychological aid. An unlaughing, untalkative child is washed with a compound decoction of Canada goldenrod.

The Nlaka’pamux of southern British Columbia and Washington’s North Cascades region recognize the antidiarrheal quality of a decoction of plant tops. The plant’s sedative quality is utilized as a pediatric aid to treat excessive crying, diarrhea or sleeplessness via bathing in a plant-based decoction.

The Okanagan of the Okanagan River Basin in present-day British Columbia and Washington prepare an infusion of rhizome shoots as a febrifuge (Latin: febris, “fever” + fugare, “to drive away”) for feverish children. A decoction of blossoms treats the flu. An infusion of flower heads is taken as an antidiarrheal remedy.

The Zuni of present-day western New Mexico appreciate Canada goldenrod’s analgesic qualities. Crushed blossoms are chewed to treat the pain of a sore threat. An infusion of crushed blossoms treats body aches and pains.

Native American ethnobotany also recognizes household and other uses for Canada goldenrod in daily life. Known to colonists as the Thompson for their association with south central British Columbia’s Thompson River, the Nlaka’pamux also apply Canada goldenrod as a veterinary aid. Horses with cuts and sores are washed with a decoction of Canada goldenrod and wild tarragon (Artemisia dracunculus).

The Okanagan discover playful aspects of Canada goldenrod as a toy and in games. Their children play with the plant’s drooping branches of clustered flower heads, using them as pretend whips.

The Ojibwe of the Upper Great Lakes region from Lake Winnipeg eastward to the Saint Lawrence Seaway value Canada goldenrod’s scabra variety as a dermatological aid. A compound poultice of flowers treats burns. Dry flowers are moistened into a poultice as an ulcer remedy. Boils are treated with a poultice of moistened, pulverized roots.

As a favorite beverage of Colonial America, Canada goldenrod still satisfies in the 21st century as a refreshing, pleasant-tasting tea that also soothes colds and respiratory ailments. Holli Richey, a Tennessee-based, registered herbalist with the American Herbalist Guild, suggests steeping 2 tablespoons of freshly chopped flowers and leaves, or 1 tablespoon of dried goldenrod, for 20 to 30 minutes in a cup of boiling water.

Canada goldenrod's scabra variety: Aomorikuma, CC BY SA 3.0, via Wikimedia Commons

Acknowledgment

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

Image credits:

Canada goldenrod, Teton County, northwestern Wyoming: Matt Lavin, CC BY SA 2.0, via Wikimedia Commons @ https://commons.wikimedia.org/wiki/File:Yellow_flowers_of_Solidago_canadensis.jpg

Canada goldenrod's scabra variety, originally named Solidago altissima as a separate species: Aomorikuma, CC BY SA 3.0, via Wikimedia Commons @ https://commons.wikimedia.org/wiki/File:Asterales_Asteraceae_Solidago_canadensis_var_scabra_Canada_goldenrod.jpg

For further information:

Abrahamson, Warren G., and Arthur E. Weis. Evolutionary Ecology Across Three Trophic Levels: Goldenrods, Gallmakers, and Natural Enemies. Monographs in Population Biology, vol. 29. Princeton NJ: Princeton University Press, 1997.

Coladonato, Milo. “Solidago Canadensis.” US Forest Service > Fire Effects Information System (FEIS) Database > Plants > Forb.
Available @ http://www.fs.fed.us/database/feis/plants/forb/solcan/all.html

Craig, Timothy P.; Joanne K. Itami; John D. Horner. “Geographic Variation in the Evolution and Coevolution of a Tritrophic Interaction.” Evolution, vol. 61, issue 5 (May 2007): 1137-1152.
Available @ http://www.bioone.org/doi/abs/10.1111/j.1558-5646.2007.00099.x

“Goldenrod Gall Fly Eurosta solidaginis.” Fairfax County Public Schools > Island Creek Elementary School > Ecology.
Available @ http://www2.fcps.edu/islandcreekes/ecology/goldenrod_gall_fly.htm

Linnaeus, Carl von. 1753. "2. Solidago canadensis." Species Plantarum, tomus II: 878. Holmiae [Stockholm, Sweden]: Laurentii Salvii [Laurentius Salvius].
Available via Biodiversity Heritage Library @ https://biodiversitylibrary.org/page/358899

Marriner, Derdriu. "Canada Goldenrod Solidago canadensis Blooms Goldenly July to October." Earth and Space News. Saturday, Aug. 27, 2016.
Available @ https://earth-and-space-news.blogspot.com/2016/08/canada-goldenrod-solidago-canadensis_27.html

Pavek, Pamela L.S. “Plant Fact Sheet for Canada Goldenrod (Solidago canadensis).” USDA Natural Resources Conservation Service (NRCS) > Plant Fact Sheet.
Available @ http://plants.usda.gov/plantguide/pdf/pg_soca6.pdf

Pavek, Pamela L.S. “Plant Guide for Canada Goldenrod (Solidago canadensis).” USDA Natural Resources Conservation Service (NRCS) > Plant Guide.
Available @ http://plants.usda.gov/plantguide/pdf/pg_soca6.pdf

“Prevent Colds with Goldenrod.” Holli Richey. Aug. 22, 2010.
Available @ https://hollirichey.com/2010/08/22/prevent-colds-with-goldenrod/

“Solidago altissima.” Iowa Plants > Flora > Family > Asteraceae > Solidago.
Available @ http://iowaplants.com/flora/family/Asteraceae/solidago/s_altissima/Solidago_altissima.html

“Solidago altissima.” Native American Ethnobotany Database > Uses.
Available @ http://naeb.brit.org/uses/search/?string=solidago+altissima

“Solidago altissima Linnaeus.” Flora of North America > Flora Taxon.
Available @ http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=242414377

“Solidago canadensis.” Missouri Botanical Garden > Gardens & Gardening > Your Garden > Plant Finder.
Available @ http://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?taxonid=277473&isprofile=1&gen=Solidago

“Solidago canadensis.” Native American Ethnobotany Database > Uses.
Available @ http://naeb.brit.org/uses/search/?string=solidago+canadensis

"Solidago canadensis L." Tropicos® > Name Search.
Available @ http://www.tropicos.org/Name/2711073

“Solidago canadensis Linnaeus.” Flora of North America > Flora Taxon.
Available @ http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=200024550

Werner, Patricia A., and William J. Platt. “Ecological Relationships of Co-Occurring Goldenrods (Solidago: Compositae).” The American Naturalist, vol. 110, no. 976 (Nov.-Dec. 1976): 959-971.
Available @ https://www.jstor.org/stable/2460024?seq=1#page_scan_tab_contents

Canada Goldenrod Solidago canadensis Blooms Goldenly July to October

Summary: Canada Goldenrod (Solidago canadensis), a New World native perennial wildflower, blooms lengthily from midsummer to autumn.

closeup of Canada goldenrod's characteristically arching plume of flowers: Robert H. Mohlenbrock/USDA Wetland Science Institute (WSI), Public Domain, via USDA NRCS PLANTS Database

Canada goldenrod (Solidago canadensis) is a New World native perennial with late and lengthy blooming that straddles two seasons, from July to October.

Canada goldenrod claims native homelands in Canada and the United States. In Canada, the perennial occurs natively in all ten provinces and in two of three territories. Canada goldenrod is not native to the northernmost territory, Nunavut.

In the United States, the native wildflower is found natively in 44 of the 50 states. Canada goldenrod is not native to Georgia, Hawaii, three (Alabama, Florida, Louisiana) of the five Gulf States, or South Carolina. The North American native also is not native to Puerto Rico or the U.S. Virgin Islands.

Canada goldenrod prefers moist habitats with full sun. The plant displays fair shade tolerance. Habitats inhabited by Canada goldenrod include fields, pastures, prairies, roadsides and thickets.

Canada goldenrod’s genus name, Solidago, derives from the Latin verb solido, which means “to make whole or heal.” The genus name reflects the reputation of many species in the genus as promoters of well-being.

Solidago canadensis is often classified as a distinct species containing five varieties. Canadensis, gilvocanescens, hargeri, salebrosa and scabra are recognized as varieties of Canada goldenrod.

Solidago canadensis is most commonly known as Canada goldenrod or Canadian goldenrod. Meadow goldenrod is another common name. Some of the other common names are associated with the wildflower’s other four varieties. The common name for the gilvocanescens variety is shorthair goldenrod. The hargeri variety is known commonly as Harger’s goldenrod. Rough goldenrod is the common name for the salebrosa variety. The scabra variety is known commonly as tall goldenrod.

The New World native’s aerial stems arise from rootlike underground stems known as rhizomes (Ancient Greek: ῥίζα, rhíza, “root”). Rhizomes range in length from 2 to 5 inches (5 to 12 centimeters).

Canada goldenrod may grow to 4 to 5 feet (1.21 to 1.52 meters), with an equiproportional spread. Sometimes Canada goldenrod has a height of over 7 feet (2.13 meters).

Stems are erect and hairless from the base up toward floral branching. Fine hairs are found on the upper plant.

Lance-shaped, sharply toothed leaves numerously alternate along the stem. Larger leaves are found on the lower stem.

As a member of the daisy or sunflower family of Asteraceae, Canada goldenrod blooms in characteristic clusters of disk and ray flowers. Flowers appear on large, horizontal branchings, known as panicles, atop the tall, firm stems. The panicles trace a pyramidal plume as branch lengths decrease toward the top.

Masses of tiny flowers, sized at about one-eighth of an inch (0.31 centimeters), open in a profusion of sunny yellow coloring, from July to October. Drooping branchings loaded densely with recurved, strap-shaped ray flowers around central, tube-shaped disk flowers create Canada goldenrod’s characteristic arching plume.

Seeds are enclosed singly within a simple dry fruit known as an achene. The capsule has sparse hairs. Bunches of pale bristles emerge from the achene’s top.

Canada goldenrod persists through wind dispersal of insect-pollinated seeds and through colony clumps formed by creeping rhizomes. Solidago canadensis is a long-lived species, with decades of persistence in established areas. In their 1976 research report, environmental biologists Patricia A. Werner, then with Michigan State University, and William J. Platt, then with the University of Illinois, noted prairie populations of Solidago canadensis, along with five other Solidago species, with a presence on the Cayler Prairie State Preserve in northwestern Iowa’s Dickinson County dating back more than 150 years.

Canada goldenrod lightly populates the sunny field that frames my yard’s northwestern edge. The wildflower’s arching plumes randomly golden the field’s lush greenery. The occurrence of wingstem (Verbesina alternifolia), another tall, yellow-flowered native plant, at separate spots in the field emphasizes the beautiful differences in floral outlines and in yellow hues.

golden stand of flowering Canada goldenrod: Harry Rose from South West Rocks, Australia, CC BY 2.0, via Wikimedia Commons

Acknowledgment

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

Image credits:

Robert H. Mohlenbrock/USDA Wetland Science Institute (WSI), Public Domain, via USDA NRCS PLANTS Database @ http://plants.usda.gov/java/largeImage?imageID=soca6_002_ahp.tif

A golden stand of flowering Canada goldenrod: Harry Rose from South West Rocks, Australia, CC BY 2.0, via Wikimedia Commons @ https://commons.wikimedia.org/wiki/File:Solidago_canadensis_flowerhead1_(16189416842).jpg

For further information:

Abrahamson, Warren G., and Arthur E. Weis. Evolutionary Ecology Across Three Trophic Levels: Goldenrods, Gallmakers, and Natural Enemies. Monographs in Population Biology, vol. 29. Princeton NJ: Princeton University Press, 1997.

Coladonato, Milo. “Solidago Canadensis.” US Forest Service > Fire Effects Information System (FEIS) Database > Plants > Forb.
Available @ http://www.fs.fed.us/database/feis/plants/forb/solcan/all.html

Craig, Timothy P.; Joanne K. Itami; John D. Horner. “Geographic Variation in the Evolution and Coevolution of a Tritrophic Interaction.” Evolution, vol. 61, issue 5 (May 2007): 1137-1152.
Available @ http://www.bioone.org/doi/abs/10.1111/j.1558-5646.2007.00099.x

“Goldenrod Gall Fly Eurosta solidaginis.” Fairfax County Public Schools > Island Creek Elementary School > Ecology.
Available @ http://www2.fcps.edu/islandcreekes/ecology/goldenrod_gall_fly.htm

Linnaeus, Carl von. 1753. "2. Solidago canadensis." Species Plantarum, tomus II: 878. Holmiae [Stockholm, Sweden]: Laurentii Salvii [Laurentius Salvius].
Available via Biodiversity Heritage Library @ https://biodiversitylibrary.org/page/358899

Marriner, Derdriu. "Wingstem Verbesina alternifolia: Bright Yellow Flowers Top Tall Stems." Earth and Space News. Saturday, Aug. 6, 2016.
Available @ https://earth-and-space-news.blogspot.com/2016/08/wingstem-verbesina-alternifolia-bright.html

Pavek, Pamela L.S. “Plant Fact Sheet for Canada Goldenrod (Solidago canadensis).” USDA Natural Resources Conservation Service (NRCS) > Plant Fact Sheet.
Available @ http://plants.usda.gov/plantguide/pdf/pg_soca6.pdf

Pavek, Pamela L.S. “Plant Guide for Canada Goldenrod (Solidago canadensis).” USDA Natural Resources Conservation Service (NRCS) > Plant Guide.
Available @ http://plants.usda.gov/plantguide/pdf/pg_soca6.pdf

“Solidago altissima.” Iowa Plants > Flora > Family > Asteraceae > Solidago.
Available @ http://iowaplants.com/flora/family/Asteraceae/solidago/s_altissima/Solidago_altissima.html

“Solidago altissima.” Native American Ethnobotany Database > Uses.
Available @ http://naeb.brit.org/uses/search/?string=solidago+altissima

“Solidago altissima Linnaeus.” Flora of North America > Flora Taxon.
Available @ http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=242414377

“Solidago canadensis.” Missouri Botanical Garden > Gardens & Gardening > Your Garden > Plant Finder.
Available @ http://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?taxonid=277473&isprofile=1&gen=Solidago

“Solidago canadensis.” Native American Ethnobotany Database > Uses.
Available @ http://naeb.brit.org/uses/search/?string=solidago+canadensis

"Solidago canadensis L." Tropicos® > Name Search.
Available @ http://www.tropicos.org/Name/2711073

“Solidago canadensis Linnaeus.” Flora of North America > Flora Taxon.
Available @ http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=200024550

Werner, Patricia A., and William J. Platt. “Ecological Relationships of Co-Occurring Goldenrods (Solidago: Compositae).” The American Naturalist, vol. 110, no. 976 (Nov.-Dec. 1976): 959-971.
Available @ https://www.jstor.org/stable/2460024?seq=1#page_scan_tab_contents

Cassiopeia the Queen Constellation Is True Arrow to Andromeda Galaxy

Summary: Cassiopeia the Queen is a northern sky constellation that points directly to the Andromeda Galaxy, the Milky Way’s closest spiral galaxy.

Constellation Cassiopeia's distinctive M/W asterism points to the Adromeda Galaxy, the Milky Way's closest spiral galaxy: EarthSky @earthskyscience via Twitter Aug. 22, 2016

The constellation of Cassiopeia the Queen of ancient Ethiopia distinctively plies Northern Hemisphere skies north of 35 degrees north latitude year-round as a circumpolar constellation. Sited on the opposite side of the North Star, Polaris, from the Great Bear's Big Dipper asterism, Cassiopeia points to the Milky Way’s closest spiral galaxy, the Andromeda Galaxy, with the constellation's M/W asterism, or distinctive pattern of stars.

Following the deeply notched V portion of the W shape leads to the Andromeda galaxy. Known officially as Messier 31, M31 or NGC 224, the Andromeda Galaxy is located about 2.5 million light years from Earth. With a diameter of 220,000 light years, the Andromeda Galaxy is double the Milky Way's diameter of 100,000 light years. The spiral galaxy has an estimated inclination of 77 degrees relative to Earth.

The Andromeda Galaxy appears to unaided eyes as a fuzzy star or a smudgy patch around a central core of light. To unaided eyes, the galaxy has the width of a full moon. The Andromeda Galaxy is the most distant object that is visible to unaided eyes.

Andromeda Galaxy, March 2, 2014: Brad Sutton/National Park Service, Public Domain, via Joshua Tree National Park @ Flickr

The distinctive M or W shape traced by the constellation’s five brightest stars qualify Cassiopeia the Seated Queen as one of the nighttime’s most easily recognizable constellations. Placement relative to Polaris determines the appearance of the five-star asterism as an M or as a W. The asterism appears as an M when above the North Star and as a W when below Polaris.

The old-fashioned name of Cassiopeia’s Chair recognizes the importance of the asterism for easy discernment of the constellation. The International Astronomical Union agreed upon Cassiopeia as the constellation’s official name for the list of 88 constellations approved by the association’s inaugural General Assembly in May 1922 in Rome, Italy. Nevertheless, the asterism’s old-fashioned name continues to provide successful guidance for succeeding generations to the chair’s exact placement in the night sky.

Of Cassiopeia’s five main telltale stars, Alpha Cassiopeiae (α Cassiopeiae; Alpha Cas, α Cas) is the brightest. The 2.24-magnitude star is sited about 230 light years away. The orange giant’s traditional name is Schedar (Arabic: şadr, “breast). As the deeply notched point in the M or W shape, Alpha Cassiopeiae serves as the true arrow that points to the Andromeda galaxy.

Of Cassiopeia’s total of 53 stars, the second brightest is Beta Cassiopeiae (ß Cassiopeiae; Beta Cas, ß Cas). Beta Cassiopeiae’s traditional names include Caph (Arabic: kaf, “palm”) and al-Sanam al-Nakah (“the camel’s hump”). White-yellow giant Caph is located about 55 light years away. Its magnitude is 2.28.

Gamma Cassiopeiae (γ Cassiopeiae; Gamma Cas, γ Cas) holds third place as a 2.47-magnitude star. Gamma Cassiopeiae is around 550 light years away. As the dip between the asterism’s two peaks, the variable blue star lies at the center of the Seated Queen’s chair.

On the Apollo 10 Flown CSM (Command and Service Module) Star Chart of Pilot John Young, Gamma Cassiopeiae is designated as Navi, in honor of Virgil Ivan “Gus” Grissom (April 3, 1926-Jan. 27, 1967). U.S. Air Force test pilot and NASA astronaut Grissom perished, along with astronauts Roger Bruce Chaffee (Feb. 15, 1935-Jan. 27, 1967) and Edward Higgins "Ed" White (Nov. 14, 1930-Jan. 27, 1967), in a fire in the Command Module interior during a pre-launch test for the Apollo 1 program.

The Seated Queen’s fourth brightest star is Delta Cassiopeia (δ Cassiopeiae; Delta Cas, δ Cas). The 2.68-magnitude star is actually an eclipsing binary star system. The larger of the starry pair is a white subgiant. Delta Cassiopeia lies about 100 light years from Earth. Its traditional name is Ruchbah (Arabic: rukbah, “knee”).

With a magnitude of 3.37, Epsilon Cassiopeiae (ε Cassiopeiae; Epsilon Cas, ε Cas) is the asterism’s and the constellation’s fifth brightest star. The blue giant is located around 400 light years away.

The asterism in Cassiopeia's constellation that points like a true arrow to Andromeda Galaxy brightens night skies with easy familiarity and visibility. The arrow's path traverses fantastic distances across time to Andromeda Galaxy's recognizable hazy patch. Each night's light from Andromeda Galaxy began the journey of visibility to Earthlings 2.5 million years ago.

Andromeda Galaxy is visible Oct. 21, 2013, to left of the fourth Unit Telescope (UT) in the European Southern Observatory's Very Large Telescope (VLT), Cerro Paranal, northern Chile; the fourth UT is known as Yepun (Mapuche: yeln, "to carry" + pun, "night": i.e., the evening star, Venus): Babak Tafreshi/European Southern Observatory, CC BY 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:

Constellation Cassiopeia's distinctive M/W asterism points to the Adromeda Galaxy, the Milky Way's closest spiral galaxy: EarthSky (@earthskyscience) via Twitter Aug. 22, 2016, @ https://twitter.com/earthskyscience/status/767740393471565824

Andromeda Galaxy, March 2, 2014: Brad Sutton/National Park Service, Public Domain, via Joshua Tree National Park @ Flickr @ https://www.flickr.com/photos/joshuatreenp/20703855582

Andromeda Galaxy, in Chilean skies, Oct. 21, 2013: Babak Tafreshi/European Southern Observatory, CC BY 2.0, via Flickr @ https://commons.wikimedia.org/wiki/File:Two_naked-eye_galaxies_above_the_VLT_(wallpaper).jpg?uselang=fr

For further information:

“Apollo 10 Flown CSM Star Chart Directly from the Personal Collection of Mission Command Module Pilot John Young, Signed and Certified.” Heritage Auctions > Historical > 2010 April Grand Format Space Exploration Auction #6037.
Available @ https://historical.ha.com/itm/transportation/space-exploration/apollo-10-flown-csm-star-chart-directly-from-the-personal-collection-of-mission-command-module-pilot-john-young-signed-and-ce/a/6037-41082.s?ts=off#Photo

Byrd, Deborah. “Locate constellation Cassiopeia the Queen.” EarthSky > Tonight. Feb. 3, 2016.
Available @ http://earthsky.org/tonight/cassiopeia-is-shaped-like-an-m-or-w

"Can you see other galaxies without a telescope?" NASA GSFC StarChild Question of the Month for November 1999.
Available @ http://starchild.gsfc.nasa.gov/docs/StarChild/questions/question15.html

“Cassiopeia Constellation.” Solar System Quick Astronomy Guide > Universe.
Available @ http://www.solarsystemquick.com/universe/cassiopeia-constellation.htm

Christoforou, Peter. “Interesting Facts about the Constellation Cassiopeia.” Astronomy Trek.
Available @ http://www.astronomytrek.com/interesting-facts-about-the-constellation-cassiopeia/

Delgado, Guillermo. "On the Meaning of Yepun: An Investigation into the Meaning of Yepun." European Southern Observatory > Telescopes & Instruments > Very Large Telescope > VLT Unit Telescope Names.
Available @ https://www.eso.org/public/usa/teles-instr/vlt/vlt-names/yepun/

EarthSky (@earthskyscience). “Tonight and in coming months … Cassiopeia points to Andromeda galaxy.” Twitter. Aug. 22, 2016.
Available @ https://twitter.com/earthskyscience/status/767740393471565824

McClure, Bruce. “Andromeda galaxy is Milky Way’s next-door neighbor.” EarthSky > Clusters Nebulae Galaxies > Science Wire. Sept. 19, 2015.
Available @ http://earthsky.org/clusters-nebulae-galaxies/andromeda-galaxy-closest-spiral-to-milky-way

McClure, Bruce. "April 2003 Feature: Cassiopeia & the Southern Cross." I Dial Stars > Astronomy & Stargazing Articles.
Available @ http://www.idialstars.com/casc.htm

McClure, Bruce. “Cassiopeia points to Andromeda galaxy.” EarthSky > Tonight. Aug. 22, 2016.
Available @ http://earthsky.org/tonight/cassiopeia-the-queen-also-points-to-andromeda-galaxy

McClure, Bruce. "More meteors? Plus Cassiopeia in the north." EarthSky > Tonight. Dec. 14, 2015.
Available @ http://earthsky.org/tonight/cassiopeia-high-in-the-north-on-winter-evenings

Schultz, David. The Andromeda Galaxy and the Rise of Modern Astronomy. New York NY; Heidelberg, Germany; Dordrecht, Netherlands; London, England: Springer, 2012.

Seedy Conyza canadensis: Prolific Seeds Produced by Canadian Horseweed

Summary: Canadian horseweed (Conyza Canadensis), a New World native annual plant with summer and winter forms, easily thrives via prolific seed production.

flowering, seeding Canadian horseweed, Karlsruhe, southwestern Germany: H. Zell, CC BY SA 3.0, via Wikimedia Commons

Canadian horseweed produces an abundance of seeds. The mean number of seeds per flower head covers a range of 60 to 70.

The stem height determines the number of flower heads per plant and, consequently, the total seed production per plant. A plant with a height of around 15 inches (40 centimeters) produces about 2,000 seeds, whereas a plant that reaches almost 5 feet (1.5 meters) may produce about 230,000 seeds.

Canadian horseweed’s morphology, or form, is conducive to wind dispersal of the plant’s seeds. A 1979 study by David L. Regehr and Fakhri A. Bazzaz of the University of Illinois at Urbana finds successful deposition of Canadian horseweed seeds onto a corn field located over 400 feet (122 meters) downwind from a thick stand of the towering green plants. A research article in 2007 by Joseph T. Dauer and David A. Mortensen at Pennsylvania State University and Mark J. Vangessel at University of Delaware reports travel distances of at least 1,640 feet (500 meters) by Canadian horseweed seeds from their source populations.

Water serves as another successful medium for dispersal of Canadian horseweed seeds. According to a 1975 study by A. D. Kelly and Victor Friedrich Bruns of the USDA Irrigated Agriculture Research and Extension Center in Prosser, Washington, field populations adjacent to irrigation canals and rivers disperse huge quantities of seeds, with a germination of 80 percent, into the waters.

Native North American ethnobotany reveals extensive uses of Canadian horseweed in medicinal remedies. For example, the Chippewa of Canada and the United States, from Lake Superior to the St. Lawrence River, decoct leaves and roots to treat stomach pain. The Hopi of northeastern Arizona apply a poultice to the temples as an analgesic remedy for headaches. The Iroquois of northeastern North America make an infusion of the whole plant and roots as an anticonvulsive and febrifuge to treat children with convulsions and fevers. The Navajo of the southwestern United States make a cold infusion or a poultice of crushed leaves as a dermatological aid for pimples and also apply a cold infusion as an anti-snake bite lotion. The Zuni of the southwestern United States crush the plants’ flowers for insertion in nostrils as a remedy that relieves rhinitis (inflammation of nasal mucous membrane) by causing sneezes.

Oil of erigeron is the essential oil that is distilled from the plant’s leaves. In American folk medicine, oil of erigeron is valued as an astringent, a diuretic and a tonic. Of the oil’s 47 volatile components, 91 percent are terpenoids, which are aromatic antioxidants. Plant-based terpenoids have traditional applications in the chemical, food and pharmaceutical industries and recent involvement in the development of biofuel products.

Canadian horseweed also has culinary applications. The Miwok of northern California pulverize raw leaves and tender tops for enjoyment as a delicacy. Modern-day foragers enjoy cooked seedlings, especially as a crunchy accompaniment to rice dishes or in salads. Crushed leaves and stems contribute a carroty scent to salads.

My yard’s claim to Canadian horseweed is a solitary plant at the northern edge of the garden bed that adorns the northwestern section of my front porch. The plant serendipitously appeared at the beginning of the summer in a propitious location next to the white 5 gallon bucket that collects rainwater from the north porch downspout.

The plant has grown unostentatiously and steadfastly throughout the summer, while its bedmates to the south have leafed, flowered and succumbed successively to their annual demises. My Canadian horseweed has patiently yielded the spotlight to the resplendent colors and forms of grape hyacinths (Muscari armeniacum), narcissus (Narcissus spp.) and tiger lilies (Hemerocallis fulva).

Now in August my Canadian horseweed measures a height halfway between 5 and 6 feet (1.52 and 1.82 meters). Great quantities of delicate white flowers adorn the plant’s top quarters. Soon the seeds, which are contained within dry fruits known as achenes, will be conspicuously topped with the fluffy pappus that serve as the secret of the plant’s successful expansion by water and wind dispersal.

In late spring, I often admired a vibrant green stand of tall Canadian horseweed in a small public garden about a mile northeast of my house. Then in June I realized that I am the proud owner of a serendipitously rooted Canadian horseweed. All summer I have wondered about the plant’s origin. Last week as I tended to Virginia juniper (Juniperus virginiana) saplings on the banks between the ephemeral creek and vernal pool along my yard’s northwestern border, I espied several Canadian horseweed plants. They were vividly green, and they were about half the height of the porch’s Canadian horseweed.

So which arrived first: the porch plant or the Creekside plants?

closeup of seeds' pappus, the secret to Canadian horseweed's easy, widespread expansion via water and wind dispersal: Patrick J. Alexander, CC BY 2.0, via USDA NRCS PLANTS Database

Acknowledgment

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

Image credits:

flowering, seeding Canadian horseweed, Karlsruhe, southwestern Germany: H. Zell, CC BY SA 3.0, via Wikimedia Commons @ https://commons.wikimedia.org/wiki/File:Conyza_canadense_001.JPG

essential oil of erigeron, Canadian horseweed, also known as Canadian fleabane: Itineranttrader, Public Domain, via Wikimedia Commons @ https://commons.wikimedia.org/wiki/File:CanadianFleabaneEssentialOil.png

closeup of seeds' pappus, the secret to Canadian horseweed's easy, widespread expansion via water and wind dispersal: Patrick J. Alexander, CC BY 2.0, via USDA NRCS PLANTS Database @ http://plants.usda.gov/java/largeImage?imageID=coca5_004_ahp.jpg

For further information:

“Canadian horseweed.” University of Florida Natural Area Teaching Laboratory > COCAN.
Available @ http://natl.ifas.ufl.edu/docs/COCAN.pdf

“Conyza – (L.) Cronquist.” Plants For A Future.
Available @ http://pfaf.org/user/Plant.aspx?LatinName=Conyza

"Conyza canadensis." Native American Ethnobotany.
Available @ http://naeb.brit.org/uses/search/?string=conyza+canadensis

“Conyza canadensis (L.) Cronquist Native Status.” USDA National Resources Conservation Service Plants Database > Plant Profile.
Available @ http://plants.usda.gov/core/profile?symbol=coca5

Dauer, Joseph T.; David A. Mortensen; Mark J. Vangessel. “Temporal and Spatial Dynamics of Long-Distance Conyza canadensis Seed Dispersal.” Journal of Applied Ecology, vol. 44, issue 1 (February 2007): 105-114.
Available @ http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2664.2006.01256.x/abstract

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

Fine, Timothy; Sean C. McKenzie; Chengci Chen; Fabian D. Menalled. “Biology, Identification, & Management of Glyphosate-Resistant Horseweed (Marestail, Conyza canadensis).” Montana State University Extension > MontGuide.
Available @ http://store.msuextension.org/publications/AgandNaturalResources/MT201608AG.pdf

“Horseweed (Conyza canadensis).” University of California Agriculture & Natural Resources Statewide Integrated Pest Management Program > Weed Gallery > Sunflower Family: Asteraceae.
Available @ http://ipm.ucanr.edu/PMG/WEEDS/horseweed.html

Kelley, A.D., and V.F. Bruns. “Dissemination of Weed Seeds by Irrigation Water.” Weed Science, vol. 23, no. 6 (November 1975): 486-493.
Available @ https://www.jstor.org/stable/4042395

Marriner, Derdriu. "Conyza canadensis: Towering Green Pillars of Canadian Horseweed." Earth and Space News. Saturday, Aug. 20, 2016.
Available @ https://earth-and-space-news.blogspot.com/2016/08/conyza-canadensis-towering-green.html

Regehr, D.L.; F.A. Bazzaz. “The Population Dynamics of Erigeron canadensis, A Successional Winter Annual.” Journal of Ecology, vol. 67 (1979): 923-933.
Available @ https://www.jstor.org/stable/2259221

Royer, France, and Richard Dickinson. Weeds of the Northern U.S. and Canada: A Guide for Identification. Edmonton Canada: The University of Alberta Press, 1999.

Tholl, Dorothea. “Biosynthesis and Biological Functions of Terpenoids in Plants.” Advances in Biochemical Engineering/Biotechnology, vol. 148 (2015): 63-106. DOI: 10.1007/10_2014_295
Available @ http://www.ncbi.nlm.nih.gov/pubmed/25583224

Tilley, Derek. “Plant Guide for Canadian horseweed (Conyza canadensis).” USDA Natural Resources Conservation Service Plants Database > Plant Guide. October 2012.
Available @ https://plants.usda.gov/plantguide/pdf/pg_coca5.pdf

Weaver, Susan E. “The Biology of Canadian Weeds. 115. Conyza canadensis.” Canadian Journal of Plant Science 81: 867-875.
Available @ http://www.nrcresearchpress.com/doi/pdf/10.4141/P00-196

Conyza canadensis: Towering Green Pillars of Canadian Horseweed

Summary: Canadian horseweed (Conyza canadensis) is a New World native plant that may grow fast and tall in a variety of habitats.

young Canadian horseweed (Conyza canadensis) prior to flowering: Rasbak, CC BY SA 3.0, via Wikimedia Commons

As a New World annual forb in the sunflower family, Asteraceae, Canadian horseweed claims homelands across North America, from Canada southward to Mexico and Central America. Canadian horseweed is found in all of the United States’ Lower 48. Canadian horseweed also occurs in two U.S. territories: Puerto Rico and the U.S. Virgin Islands.

In Canada, Canadian horseweed thrives in all ten provinces. In the easternmost province of Newfoundland and Labrador, Canadian horseweed occurs natively on the island of Newfoundland but not in Labrador, the mainland’s portion of the province. Canadian horseweed is found natively in Canada’s Northwest Territories. It does not occur natively in Canada’s other two territories, Nunavut and Yukon.

Canadian horseweed also claims homelands on the Overseas Collectivity of Saint Pierre and Miquelon (Collectivité d’Outre-mer de Saint Pierre et Miquelon). The small northwestern Atlantic archipelago of eight islands lies at the entrance of Fortune Bay, off the southwestern coast of the island of Newfoundland.

Canadian horseweed’s scientific name is Conyza canadensis. Another accepted scientific synonym is Erigeron canadensis.

Alternative common names for Canadian horseweed include Canadian fleabane, coltstail and marestail. The common name of fleabane acknowledges the plant’s presumed repugnance to fleas. Common names of coltstail and marestail reflect its presumed resemblance to a horse’s tail.

Canadian horseweed favors well-drained, sunny habitats, with neutral to alkaline soils, in grasslands as well as in such disturbed moist sites as abandoned agricultural lands; floodplains; riparian, or riverbank, areas; urban locales; wetlands; woodland paths. Habitats that feature Canadian horseweed include old fields, orchards, railways, roadsides and vineyards.

The New World native, however, adapts to a variety of environments beyond its comfort zones, including non-wetlands, poor soils and semi-shade. Canadian horseweed is able to tolerate drought. It also appears as an early successional species after forest clearcutting.

Synecology (frequent plant community associations) reveals floral camaraderie with New World peppercresses (Lepidium spp.). Canadian horseweed also appears in communities of such naturalized Old World annuals and biennials as shepherd’s purse (Capsella bursa pastoris), henbit deadnettle (Lamium amplexicaule) and prickly lettuce (Lactuca serriola).

As a herbaceous flowering plant that lacks grass-like features, Canadian horseweed is considered botanically as a forb. Canadian horseweed is described botanically as both a summer and a winter annual forb. Summer Canadian horseweeds germinate in spring while winter forms germinate in the autumn.

The New World annual displays a range of heights, depending upon soil poorness or richness. In natively favored soils, Conyza canadensis may soar to heights in a dramatic range from 5 feet (1.5 meters) to 10 feet (3.048 meters).

Narrow, unstalked leaves whorl alternately around the forb’s slender stem. Leaves have a lance-like shape.

Flowering occurs in mid to late summer as loose, branching clusters known as panicles. Flower heads measure a diminutive height of 0.08 to 0.16 inches (2 to 4 millimeters) and a miniature width of 0.12 to 0.28 inches (3 to 7 millimeters).

Canadian horseweed’s small flower heads consist of numerous, ray flowers. The tiny rays display purplish or white colors. Each ray flower is remarkably small, with lengths measuring no more than 0.02 to 0.04 inches (0.5 to 1.0 millimeters).

Towering green pillars of Canadian horseweed define summer’s landscapes. Delicately colored white and purplish flowers wink from clustered flower heads at the top of perfectly postured, slender, tall stems.

The solitary, wind-seeded Canadian horseweed in the garden strip along the northeastern extent of my front porch stands straight and tall as it outlives this year’s series of grape hyacinths, narcissus and tiger lilies.

flowering Canadian horseweed, Rock Creek Park, Washington DC: Fritzflohrreynolds, CC BY SA 3.0, via Wikimedia Commons

Acknowledgment

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

Image credits:

Canadian horseweed prior to flowering: Rasbak, CC BY SA 3.0, via Wikimedia Commons @ https://commons.wikimedia.org/wiki/File:Canadese_fijnstraal_plant_Conyza_canadensis.jpg

flowering Canadian horseweed, Rock Creek Park, Washington DC: Fritzflohrreynolds, CC BY SA 3.0, via Wikimedia Commons @ https://commons.wikimedia.org/wiki/File:Conyza_canadensis_-_Canadian_horseweed.jpg?uselang=fr

For further information:

“Canadian horseweed.” University of Florida Natural Area Teaching Laboratory > COCAN.
Available @ http://natl.ifas.ufl.edu/docs/COCAN.pdf

“Conyza – (L.) Cronquist.” Plants For A Future.
Available @ http://pfaf.org/user/Plant.aspx?LatinName=Conyza

“Conyza canadensis (L.) Cronquist Native Status.” USDA National Resources Conservation Service Plants Database > Plant Profile.
Available @ http://plants.usda.gov/core/profile?symbol=coca5

"Conyza canadensis." Native American Ethnobotany.
Available @ http://naeb.brit.org/uses/search/?string=conyza+canadensis

Dauer, Joseph T.; David A. Mortensen; Mark J. Vangessel. “Temporal and Spatial Dynamics of Long-Distance Conyza canadensis Seed Dispersal.” Journal of Applied Ecology, vol. 44, issue 1 (February 2007): 105-114.
Available @ http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2664.2006.01256.x/abstract

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

Fine, Timothy; Sean C. McKenzie; Chengci Chen; Fabian D. Menalled. “Biology, Identification, & Management of Glyphosate-Resistant Horseweed (Marestail, Conyza canadensis).” Montana State University Extension > MontGuide.
Available @ http://store.msuextension.org/publications/AgandNaturalResources/MT201608AG.pdf

“Horseweed (Conyza canadensis).” University of California Agriculture & Natural Resources Statewide Integrated Pest Management Program > Weed Gallery > Sunflower Family: Asteraceae.
Available @ http://ipm.ucanr.edu/PMG/WEEDS/horseweed.html

Kelley, A.D., and V.F. Bruns. “Dissemination of Weed Seeds by Irrigation Water.” Weed Science, vol. 23, no. 6 (November 1975): 486-493.
Available @ https://www.jstor.org/stable/4042395

Regehr, D.L.; F.A. Bazzaz. “The Population Dynamics of Erigeron canadensis, A Successional Winter Annual.” Journal of Ecology, vol. 67 (1979): 923-933.
Available @ https://www.jstor.org/stable/2259221

Royer, France, and Richard Dickinson. Weeds of the Northern U.S. and Canada: A Guide for Identification. Edmonton Canada: The University of Alberta Press, 1999.

Tholl, Dorothea. “Biosynthesis and Biological Functions of Terpenoids in Plants.” Advances in Biochemical Engingeering/Biotechnology, vol. 148 (2015): 63-106. DOI: 10.1007/10_2014_295
Available @ http://www.ncbi.nlm.nih.gov/pubmed/25583224

Tilley, Derek. “Plant Guide for Canadian horseweed (Conyza canadensis).” USDA Natural Resources Conservation Service Plants Database > Plant Guide. October 2012.
Available @ https://plants.usda.gov/plantguide/pdf/pg_coca5.pdf

Weaver, Susan E. “The Biology of Canadian Weeds. 115. Conyza canadensis.” Canadian Journal of Plant Science 81: 867-875.
Available @ http://www.nrcresearchpress.com/doi/pdf/10.4141/P00-196