Senecio triangularis

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Senecio triangularis
Senecio triangularis 0613.JPG
Senecio triangularis in Mount Rainier National Park
Scientific classification edit
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Asterids
Order: Asterales
Family: Asteraceae
Genus: Senecio
S. triangularis
Binomial name
Senecio triangularis

Senecio gibbonsii Greene
Senecio saliens Rydberg
Source: IPNI,[1] FNA.[2]

Senecio triangularis, known as arrowleaf ragwort,[3] arrowleaf groundsel and arrowleaf butterweed, is a species of the genus Senecio and family Asteraceae.


The green involucral bracts have black tips with hairy tufts.[4]

It is similar in form to Senecio serra, both being four feet tall, have narrow and serrated leaves, and are topped with many small, yellow sunflowers. but S. triangularis is more common than S. serra.[5] S. triangularis has single erect stems, reaching up to 10–120 cm (4–47 in) tall.[6] The stems have evenly distributed leaves.[2] The leaves are triangular, with tapered ends,[2][5] hence the name. The flowers have a prominent central dome,[5] with ray florets around 8 cm wide.[2]

As some plants are diploid, meaning having two sets of chromosomes, this can be used to identify hybrids and classification of groupings. It has been counted as 2n = 40, 80.[2]


It has the common names of arrowleaf ragwort, arrowleaf groundsel,[6] and arrowleaf butterweed.

In the early 1930s, Scottish botanist Thomas Drummond collected this plant, probably on his second trip to the United States The plant was the named by William Hooker, Drummond's mentor, and first published and described by Hooker in 'Flora Boreali-Americana' (Fl. Bor.-Amer.) Vol.1 on page 332 in 1834.[2][5]

Distribution and habitat[edit]

It is native to temperate regions of America.[7]


Subarctic America: Northwest Territory, Yukon Territory, Alaska
Western Canada: Alberta, British Columbia
Northwestern United States: Colorado, Idaho, Montana, Oregon, Washington, Wyoming
Southwestern United States: Arizona, California, Nevada, Utah, New Mexico

Source: GRIN,[7]


It grows in open woodlands, (mainly coniferous forests) and on rocky stream sides.[2][5] They can grow at altitudes of between 100 to 3,500 m (330 to 11,480 ft).[2]


  1. ^ International Plant Names Index (IPNI). Royal Botanic Gardens, Kew Retrieved 2008-05-27. Missing or empty |title= (help)
  2. ^ a b c d e f g h Flora of North America. "45. Senecio triangularis Hooker". Retrieved 2008-05-27.
  3. ^ "Senecio triangularis". Natural Resources Conservation Service PLANTS Database. USDA. Retrieved 10 November 2015.
  4. ^ Pojar, Jim; Andy MacKinnon (1994). Plants of the Pacific Northwest. Lone Pine Publishing. p. 298. ISBN 1-55105-042-0.
  5. ^ a b c d e "YELLOW FLOWERS". Retrieved 23 July 2017.
  6. ^ a b "Arrow-leaf Groundsel - Senecio triangularis". Retrieved 23 July 2017.
  7. ^ a b "Senecio triangularis". Germplasm Resources Information Network (GRIN). Agricultural Research Service (ARS), United States Department of Agriculture (USDA). Retrieved 2008-05-27.

External links[edit]

Media related to Senecio triangularis at Wikimedia Commons