Senecio triangularis

{{Short description|Species of flowering plant}}

{{Speciesbox

| image = Senecio_triangularis_0613.JPG

| image_caption = Senecio triangularis in Mount Rainier National Park

| status = {{TNCStatus}}

| status_system = TNC

| taxon = Senecio triangularis

| authority = Hooker

| synonyms = Senecio gibbonsii Greene

Senecio saliens Rydberg

Source: IPNI,{{IPNI

| id = 248228-1

| date = 2008-05-27

| title = Senecio viscosissimus

|

}} FNA.{{cite web

| url = http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=250067515

| title = 45. Senecio triangularis Hooker

| access-date = 2008-05-27

| author = Flora of North America

| authorlink = Flora of North America

}}|

}}

Senecio triangularis, known as arrowleaf ragwort,{{PLANTS|id=SETR|taxon=Senecio triangularis|accessdate=10 November 2015}} arrowleaf groundsel and arrowleaf butterweed, is a species of the genus Senecio and family Asteraceae.

Description

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.{{cite web|title=YELLOW FLOWERS |url=https://www.swcoloradowildflowers.com/Yellow%20Enlarged%20Photo%20Pages/senecio%20serra%20and%20triangularis.htm|publisher=swcoloradowildflowers.com|access-date=23 July 2017}} S. triangularis has single erect stems, reaching up to {{convert|10-120|cm|0|abbr=on}} tall. The stems have evenly distributed leaves. The leaves are up to {{Convert|20|cm|abbr=on|frac=2}} long and triangular with tapered ends, hence the name.{{Cite book |last=Spellenberg |first=Richard |url=https://archive.org/details/nationalaudubons00spel/page/395/ |title=National Audubon Society Field Guide to North American Wildflowers: Western Region |publisher=Knopf |year=2001 |isbn=978-0-375-40233-3 |edition=rev |pages=397 |orig-date=1979}}

The green involucral bracts have black tips with hairy tufts.{{cite book | last = Pojar | first = Jim |author2=Andy MacKinnon | title = Plants of the Pacific Northwest | publisher = Lone Pine Publishing | page = 298 | date = 1994 | isbn = 1-55105-042-0}} On display from June to September, the yellow flower heads are up to {{Convert|4|cm|abbr=on|frac=4}} wide, with about 8 rays around a disk.

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.

{{gallery|mode=packed

|Senecio_triangularis_0609.JPG|Flower close-up

}}

Taxonomy

It has the common names of arrowleaf ragwort, arrowleaf groundsel,{{cite web|title=Arrow-leaf Groundsel - Senecio triangularis|url=http://fieldguide.mt.gov/speciesDetail.aspx?elcode=PDAST8H360|publisher=fieldguide.mt.gov|access-date=23 July 2017}} and arrowleaf butterweed.

In the early 1830s, Scottish botanist Thomas Drummond collected this plant, probably on his second trip to the United States. The plant was named by Drummond's mentor, William Jackson Hooker, who first published and described it in 1834.

Distribution and habitat

It is native to temperate regions of America:{{GRIN|accessdate=2008-05-27}}

:

:Nearctic:

::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

It grows in open woodlands, (mainly coniferous forests) and on rocky stream sides. They can grow at altitudes of between {{convert|100|and|3500|m|ft|abbr=on}}.

Ecology

It is reportedly poisonous to animals.{{Cite book|last=Reiner|first=Ralph E.|title=Introducing the Flowering Beauty of Glacier National Park and the Majestic High Rockies|publisher=Glacier Park, Inc.|year=1969|pages=44}}

References

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