Senecio congestus

Senecio congestus, also known by its common names Swamp Ragwort, Northern Swamp Groundsel, Marsh Fleabane, Marsh Fleawort, Clustered Marsh Ragwort and Mastodon Flower, a herbaceous member of the Asteraceae family and the Senecio genus, can be seen most easily when its bright yellow umbrel flowers appear from May to early July standing 3 feet (0.91 m) to 4 feet (1.2 m) along marshes, stream banks and slough areas where it likes to grow.⁴

Description

Like many of the Senecio genus S. congestus can be an annual or biennial and perhaps rarely perennial, depending on the conditions.² A villous broad leafed plant with a single⁵ hollow stem and favoring mud flats like Marsh Groundsel (Senecio hydrophilus) but not alike in that Marsh Ragwort cannot tolerate alkaline sites nor standing water.⁶

In the early stages of growth, the leaves, stem, and flower heads are all covered with translucent hairs, producing a "greenhouse effect" close to the surface of the plant, essentially extending the growing season by a few vital days by allowing the sun to warm the tissues, and preventing the heat from escaping.⁷

Leaves and stems: An erect plant ⁵ standing 6 inches (15 cm) to 60 inches (150 cm) tall, S. congestus varies as much in stature as it does in the distribution & the persistence of its tomentum (the closely matted or fine hairs on plant leaves). ² Sparse to dense villous stems are more hollow towards the base;⁶ hairs that are white, light yellowish, or reddish brown.² Basal and cauline² leaf edges mostly toothless or with a few coarse teeth⁵ that sometimes wither before flowering.² The leaves all basically similar in shape, oblong with the lower ones often spatulate, 1.6 inches (4 cm) to 8 inches (20 cm) long, .2 inches (0.5 cm) to 2.5 inches (6 cm) wide, with the basal leaves occasionally larger, glabrous or villous in patches, rounded at the tips, toothed, often deciduous with clasping bases.⁶

Flowers: "Congested" clusters of several to many pale yellow flower heads⁶ that sometimes appear tubular and incompletely opened.² a branched inflorescence,⁵ with 13 to more than 21 flower heads per stalk. Each flower head is .25 inches (6 mm) to .5 inches (10 mm) across and .16 inches (4 mm) to .4 inches (10 mm) in length,², with small but obvious rays⁵ in a corolla laminae surrounded by (usually) 21 green or yellowish green, pink tipped bracts² which can be scarious toward the tips.⁶

Seeds: Typical of the Senecio genus, S. congestus produces strongly accrescent⁶ one-seeded, one-celled,² 1.5 millimetres to 2.5 millimetres long⁶ dry achenes⁵ on very fine & numerous,⁶ white or dirty white,² fluffy,⁵ pappus bristles.⁶ The seeds have been shown to survive in the soil for more than a year but less than 5 years, the maximum longevity unknown.⁸

Common names

Distribution

Senecio congestus plants itself in areas that have freezing winters¹ and in moist to wet soils, such as damp meadows, swamps, sandy pond edges⁵ and roadside ditches¹⁴ at altitudes of 0 feet (0 m) to 3,300 feet (1,000 m)² It is the most common annual plant species in the eastern Canadian Arctic.⁷

Noxious and toxic

Toxicity: Unlike many in the Senecio genus Marsh Ragwort is considered a vegetable and safe for human consumption;¹³ the young leaves and flowering stems of Senecio congestus can be eaten raw as salad, cooked as a potherb or made into a "sauerkraut",¹⁵

Noxiousness: Senecio congestus does appear on a list of North Dakota plants to be monitored,⁴ however, it tends to be more of a plant the presence of which indicates severe disturbance such as over-foraging and hyper-salinity, as is the case of the habitats of arctic geese where the forage plants are disappearing. Two locations are mentioned by United States Fish and Wildlife Service (USFWS) having problems from the ever expanding populations of arctic geese¹⁶ and one from the Arctic Institute of North America of the University of Calgary¹⁷ or from an unpublished report from the Canadian Wildlife Service made available by the USFWS¹⁸:

Subspecies which are synonyms

References

^ ^a ^b ^c ^d ^e ^f ^g ^h Natural Resources Conservation Service (NRCS). "PLANTS Profile, Senecio congestus (R. Br.) DC." (HTML). The PLANTS Database. United States Department of Agriculture. Retrieved on 2008-02-16.
^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l ^m Flora of North America. "Flora of North America Tephroseris palustris (Linnaeus)" (HTML). Retrieved on 2008-02-16.
^ The International Plant Names Index. "Details Othonna palustris L" (HTML). Plant Names. Retrieved on 2008-02-16.
^ ^a ^b NDSU Extension Service. "Swamp ragwort" (HTML). ND Noxious & Troublesome Weeds. North Dakota State University USDA Cooperative extension service. Retrieved on 2008-02-23. "Swamp ragwort has been increasing in frequency recently and infestations should be monitored even though the plant generally is not considered invasive."
^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ University of Wisconsin - Stevens Point. "Senecio congesta" (HTML). Robert W. Freckmann Herbarium. Retrieved on 2008-02-16.
^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k US Geological Survey (2006-08-03). "1. Senecio congestus (R.Br.) DC. -- Swamp ragwort" (HTML). 14. Senecio L.-- Ragwort; 49. Asteraceae, the Aster Family; Aquatic and Wetland Vascular Plants of the Northern Great Plains. United States Department of the Interior. Retrieved on 2008-02-12.
^ ^a ^b S.G. Aiken, M.J. Dallwitz, L.L. Consaul, C.L. McJannet, L.J. Gillespie, R.L. Boles, G.W. Argus, J.M. Gillett, P.J. Scott, R. Elven, M.C. LeBlanc, A.K. Brysting and H. Solstad (2003-05-29). "Tephroseris palustris (L.) Fourr. subsp. congesta (R.Br.) Holub" (HTML). Flora of the Canadian Arctic Archipelago. Canadian Museum of Nature. Retrieved on 2008-02-23.
^ Thompson, K., Bakker, J.P. and Bekker, R.M. (1997). "The Soil Seed Banks of North West Europe: Methodology, density and Longevity" (HTML). Cambridge University Press, Cambridge.. Retrieved on 2008-02-24.
^ Integrated Taxonomic Information System Organization (ITIS). "Senecio congestus (R. Br.) DC." (HTML). Integrated Taxonomic Information System on-line database. Retrieved on 2008-02-16.
^ "RC0154-09". Retrieved on 2008-02-23.
^ Elaine A. Nowick. "Senecio congestus (R.Br.) DC." (HTML). Historical Common Names of Great Plains Plants. Retrieved on 2008-02-23.
^ ^a ^b ^c Botanic Garden and Botanical Museum Berlin-Dahlem. "Details for: Tephroseris palustris (L.) Rchb." (HTML). Euro+Med PlantBase. Freie Universität Berlin. Retrieved on 2008-02-26.
^ ^a ^b Germplasm Resources Information Network (GRIN) (2007-05-03). "Taxon: Tephroseris palustris (L.) Rchb." (HTML). Taxonomy for Plants. USDA, ARS, National Genetic Resources Program, National Germplasm Resources Laboratory, Beltsville, Maryland. Retrieved on 2008-02-23.
^ "Senecio congestus (R. Br.) DC / Крестовник скученный" (HTML) (in Russian) (2005-03-12). Retrieved on 2008-02-23.
^ Porsild, A.E. (1953), Edible Plants of the Arctic, pp. 15-34 (p. 27)
^ ARCTIC GOOSE HABITAT WORKING GROUP. "STATUS OF HABITAT AT SELECTED BREEDING AND STAGING SITES" (HTML). ARCTIC ECOSYSTEMS IN PERIL. Retrieved on 2008-02-23.
^ Alisauskas, Ray T.; Charlwood, Jason W.; Kellett, Dana K. (2006-06-01). "Vegetation correlates of the history and density of nesting by Ross's geese and lesser snow geese at Karrak Lake, Nunavut." (HTML). Encyclopedia.com. HighBeam Research, Gale Group, Farmington Hills, Michigan. Retrieved on 2008-02-23.
^ Andrew B. Didiuk, Ray T. Alisauskas, Robert F. Rockwell (2002). "INTERACTION WITH ARCTIC AND SUBARCTIC HABITATS" (HTML). Retrieved on 2008-02-24.
^ "Karrak Lake, Nunavut -- Google Maps" (HTML). Retrieved on 2008-02-24.

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