Description ⁵

With dandelion-like yellow flowers, this annual plant grows a single, sometimes branched stem from a small taproot that is easily pulled. The normally 20 to 60 cm high plant has alternate leaves that get smaller toward the top. Basal leaves are stalked and toothed; stem leaves are stalkless and mostly linear.

Range in Yukon ⁵

Narrowleaf Hawksbeard occurs throughout Yukon along all the major highways. This species has been found over 1 km from roadways and along rivers. This plant does not compete well in undisturbed sites, but readily colonizes frequently disturbed sites such as roadsides and rivers.

Similar Species ⁵

Spiny Sow Thistle (Sonchus asper) is known only from Haines Junction and the La Biche River. This is also an annual plant with a short taproot.

Ecological Impact ⁵

Each plant produces more than 49,000 seeds; open areas and disturbed sites are readily colonized.

Control ⁵

Annual plants require prevention of seed production and prevention of dispersal. Narrowleaf Hawksbeard is easily pulled up by hand. The plants will continue to mature after being pulled. Therefor plants should be placed in plastic bags to roast the seeds. Mechanical and chemical methods can also be used to control this plant. It is a prolific seed producer that once established is hard to remove.

For more information visit: Yukon Invasive Species Council

Sources and Credits

1. (c) L.G. Johanson, some rights reserved (CC BY-NC), uploaded by L.G. Johanson
2. (c) Kari Pihlaviita, some rights reserved (CC BY-NC-SA), http://farm8.staticflickr.com/7247/7486737536_fafa08cb1e_o.jpg
3. (c) Dan Mullen, some rights reserved (CC BY-NC-ND), https://www.flickr.com/photos/8583446@N05/2613535538/
4. (c) 2014 Richard Spellenberg, some rights reserved (CC BY-NC-SA), http://calphotos.berkeley.edu/cgi/img_query?seq_num=598800&one=T
5. (c) L.G. Johanson, some rights reserved (CC BY-SA)

More Info

• iNaturalist.ca taxon page
• Biodiversity Heritage Library
• BOLD Systems BIN search
• Calflora
• CalPhotos
• eFloras.org
• Flora of North America (beta)
• Global Biodiversity Information Facility (GBIF)
• Go Botany
• HOSTS - a Database of the World's Lepidopteran Hostplants
• IPNI (with links to POWO, WFO, and BHL)
• Jepson eFlora
• NatureServe Explorer 2.0
• NBN Atlas
• SEINet Symbiota portals
• Tropicos
• USDA PLANTS database
• VASCAN by Canadensys
• World Flora Online
• 日本のレッドデータ検索システム
• 植物和名−学名インデックス YList

Range Map

(c) NatureServe, some rights reserved (CC-BY-NC)

iNaturalist.ca Map