OregonFlora: Senecio sylvaticus vs. Senecio clarkianus

	Senecio sylvaticus	Senecio clarkianus
	wood groundsel, woodland ragwort
Habit	Herbs annual, (1.5)3–8+ dm; from fibrous taproots.
Stems	1, densely pubescent with abundant curly hairs.
Leaves	evenly distributed along stems, obovate to oblong in outline, bases tapering, usually 1–2-pinnately lobed or divided, ultimate margins dentate; proximal petiolate; distal clasping and bract-like.
Inflorescences	corymb-like arrays; bracts 0 or inconspicuous.
Involucres	cylindric.
Ray florets	0, rarely 1–8; rays 1–2+ mm.
Disc florets	40–50.
Phyllaries	13+, rarely 21, 4–7+ mm; tips green or minutely black.
Calyculi	0 or 1–5+ linear to filiform bractlets, 2–3 mm.
Fruits	1.5–2.5 mm, sparsely pubescent on ribs.
Heads	12–24.
2n	=40.

	Senecio sylvaticus	Senecio clarkianus
Distribution	[WildflowerSearch map] [BONAP county map]	[WildflowerSearch map] [BONAP county map]
Discussion	Disturbed open wooded areas. Flowering May–Oct. 0–1200 m. Casc, CR, ECas, Est, Sisk, WV. CA, WA; north to British Columbia, scattered in eastern North America; Asia, Europe. Exotic. Senecio sylvaticus is a native of Eurasia and favors cool, damp climates. In overall appearance, it resembles the more common S. vulgaris. However, the latter has distinctive black-tipped phyllaries, while S. sylvaticus has phyllaries that are generally green-tipped. This species is well established in the Pacific Northwest and in parts of eastern Canada. Elsewhere it is sporadic.
Source	Flora of Oregon, volume 2, page 341 Debra Trock
Sibling taxa	S. aronicoides, S. crassulus, S. ertterae, S. fremontii, S. hydrophiloides, S. hydrophilus, S. integerrimus, S. jacobaea, S. serra, S. sphaerocephalus, S. triangularis, S. viscosus, S. vulgaris	S. aronicoides, S. crassulus, S. ertterae, S. fremontii, S. hydrophiloides, S. hydrophilus, S. integerrimus, S. jacobaea, S. serra, S. sphaerocephalus, S. sylvaticus, S. triangularis, S. viscosus, S. vulgaris
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: CA 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

Senecio clarkianus

wood groundsel, woodland ragwort

Habit

Herbs annual, (1.5)3–8+ dm; from fibrous taproots.

Stems

1, densely pubescent with abundant curly hairs.

Leaves

evenly distributed along stems, obovate to oblong in outline, bases tapering, usually 1–2-pinnately lobed or divided, ultimate margins dentate;

proximal petiolate;

distal clasping and bract-like.

Inflorescences

corymb-like arrays;

bracts 0 or inconspicuous.

Involucres

cylindric.

Ray florets

0, rarely 1–8;

rays 1–2+ mm.

Disc florets

40–50.

Phyllaries

13+, rarely 21, 4–7+ mm;

tips green or minutely black.

Calyculi

0 or 1–5+ linear to filiform bractlets, 2–3 mm.

Fruits

1.5–2.5 mm, sparsely pubescent on ribs.

Heads

12–24.

=40.

Senecio clarkianus

Distribution

[WildflowerSearch map]

[BONAP county map]

[WildflowerSearch map]

[BONAP county map]

Discussion

Disturbed open wooded areas. Flowering May–Oct. 0–1200 m. Casc, CR, ECas, Est, Sisk, WV. CA, WA; north to British Columbia, scattered in eastern North America; Asia, Europe. Exotic.

Senecio sylvaticus is a native of Eurasia and favors cool, damp climates. In overall appearance, it resembles the more common S. vulgaris. However, the latter has distinctive black-tipped phyllaries, while S. sylvaticus has phyllaries that are generally green-tipped. This species is well established in the Pacific Northwest and in parts of eastern Canada. Elsewhere it is sporadic.

Source

Flora of Oregon, volume 2, page 341
Debra Trock

Sibling taxa