Burke: Senecio sylvaticus vs. Senecio serra

	Senecio sylvaticus	Senecio serra
	wood groundsel, woodland groundsel, woodland ragwort	tall butterweed, butterweed groundsel
Habit	Sparsely pubescent, tap-rooted annual, usually with a simple stem 1.5-8 dm. tall	Stout, glabrous, fibrous-rooted perennial 5-20 dm. tall, stems clustered.
Leaves	Leafy throughout, the leaves more or less pinnatifid and irregularly toothed, 2-12 cm. long and 4-40 mm. wide, narrowly lanceolate in outline.	Numerous, not tufted toward the base, not much reduced upward, the lower leaves oblanceolate, short-petiolate, early deciduous, the others lanceolate, tapering to a short petiole, 5-15 cm. long and 1-4 cm. wide, sharply toothed.
Flowers		Heads numerous on short peduncles, almost cylindric, the disk 3-7 mm. wide; involucre 6-8 mm. high, its bracts about 8 or about 13, often black-tipped; rays few, about 5 or 8, 5-8 mm. long, yellow.

	Senecio sylvaticus	Senecio serra
Identification notes	Separate from the only other annual Senecio in our area by the number of involucre bracts (S. vulgaris has about 21, S. sylvaticus,13), the bracteoles (only S. vulgaris are black-tipped) and the aroma (only S. sylvaticus is malodorous).	Look for a tall, upright plant with large, sharply toothed leaves the length of the stem.
Flowering time	May-September	June-August
Habitat	Roadsides, fields, forest edge, wastelots, and other disturbed areas at low elevation.	Meadows and open, moist hillsides, foothills to mid-elevations in the mountains.
Distribution	Occurring chiefly west of the Cascades crest in Washington; British Columbia to California, also in eastern North America. [WildflowerSearch map] [BONAP county map]	Occurring chiefly east of the Cascades crest in Washington; Washington to California, east to Montana, Wyoming, and Colorado. [WildflowerSearch map] [BONAP county map]
Origin	Introduced from Europe	Native
Conservation status	Not of concern	Not of concern
Sibling taxa	S. elmeri, S. fremontii, S. hydrophiloides, S. hydrophilus, S. integerrimus, S. lugens, S. neowebsteri, S. serra, S. triangularis, S. viscosus, S. vulgaris	S. elmeri, S. fremontii, S. hydrophiloides, S. hydrophilus, S. integerrimus, S. lugens, S. neowebsteri, S. sylvaticus, S. triangularis, S. viscosus, S. vulgaris
Subordinate taxa		S. serra var. serra
Web links	Local floras: BC, CA, OR, WA Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search	Local floras: OR, WA Local Web sites: Flora NW, PNW Herbaria, Turner Photog. WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Senecio serra

wood groundsel, woodland groundsel, woodland ragwort

tall butterweed, butterweed groundsel

Habit

Sparsely pubescent, tap-rooted annual, usually with a simple stem 1.5-8 dm. tall

Stout, glabrous, fibrous-rooted perennial 5-20 dm. tall, stems clustered.

Leaves

Leafy throughout, the leaves more or less pinnatifid and irregularly toothed, 2-12 cm. long and 4-40 mm. wide, narrowly lanceolate in outline.

Numerous, not tufted toward the base, not much reduced upward, the lower leaves oblanceolate, short-petiolate, early deciduous, the others lanceolate, tapering to a short petiole, 5-15 cm. long and 1-4 cm. wide, sharply toothed.

Flowers

Heads numerous on short peduncles, almost cylindric, the disk 3-7 mm. wide;

involucre 6-8 mm. high, its bracts about 8 or about 13, often black-tipped;

rays few, about 5 or 8, 5-8 mm. long, yellow.

Senecio sylvaticus

Senecio serra

Identification notes

Separate from the only other annual Senecio in our area by the number of involucre bracts (S. vulgaris has about 21, S. sylvaticus,13), the bracteoles (only S. vulgaris are black-tipped) and the aroma (only S. sylvaticus is malodorous).

Look for a tall, upright plant with large, sharply toothed leaves the length of the stem.

Flowering time

May-September

June-August

Habitat

Roadsides, fields, forest edge, wastelots, and other disturbed areas at low elevation.

Meadows and open, moist hillsides, foothills to mid-elevations in the mountains.

Distribution