[Butterweeds, Groundsels and Ragworts: The Genera Packera and Senecio in the Columbia
River Gorge of Oregon and Washington]
Arrowleaf Groundsel, Arrow-leaf Groundsel, Arrowleaf Ragwort
Synonyms: Senecio triangularis var. angustifolius
The photo above shows a close-up view from above of the flowerhead of arrow-leaf butterweed. 6-8 narrow ray flowers typically line theee outside of the narrow, central cluster of disk flowers. Photographed in meadows along Crofton Creek, along the Crofton Ridge Trail #73.......July 16, 2006.
The photo at right shows a close-up of the involucral bracts of arrow-leaf butterweed. Photographed in meadows along Crofton Creek, along the Crofton Ridge Trail #73........July 16, 2006. Note that the narrow bracts are glabrous with only a few of them tipped with a dark spot.
Arrowleaf groundsel has numerous, soft, green arrowhead shaped leaves found
along the many stems that make up this plant. It ranges in size from 30-150
cm in height. The herbage is mostly smooth or glabrous. The leaves are narrowly
to broadly triangular in shape, with long petioles, although the upper may become
sessile. The leaf blades are coarsely toothed, and are 4-20 cm long and from
2-10 cm wide. The several to numerous flower heads are at the top of the plant
in a flat-topped inflorescence. The involucre is 7-10 mm tall with 8-13 bracts.
The 5-8 rays are yellow and 7-13 mm long. The disk flowers are yellow. It flowers
from June to September.
Arrow-leaf groundsel is eaten by deer, elk, and sheep.
Moderate to high elevation streambanks and other wet areas in the mountains,
especially those that are cool and moist.
Arrowleaf groundsel is widespread within its habitat in the west.
In the Columbia River Gorge, it is found between 100'-4300' from Crown Pt.
in the west to about the Little White Salmon River in the east.
The photo above shows arrow-leaf butterweed as seen at Island Springs on the east side of Mt. Adams........August 12, 2006. Note the narrowly triangular leaves with serrate margins.