OregonFlora: Senecio sylvaticus vs. Senecio ertterae

	Senecio sylvaticus	Senecio ertterae
	wood groundsel, woodland ragwort	Ertter's groundsel
Habit	Herbs annual, (1.5)3–8+ dm; from fibrous taproots.	Herbs annual, 2–5(6+) dm; taproots twisting, thin.
Stems	1, densely pubescent with abundant curly hairs.	usually 1, rarely clustered, subsucculent, unevenly tomentose to glabrate.
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.	basal withering early; cauline oblanceolate to spatulate, bases tapering; margins deeply incised; petioles winged; distal sessile and bract-like, progressively reduced.
Inflorescences	corymb-like arrays; bracts 0 or inconspicuous.	cyme-like arrays; bracts 0 or few and inconspicuous.
Involucres	cylindric.	widely cylindric.
Ray florets	0, rarely 1–8; rays 1–2+ mm.	8, rarely 13; rays 5–6 mm.
Disc florets	40–50.	45–55.
Phyllaries	13+, rarely 21, 4–7+ mm; tips green or minutely black.	usually 13, 6–7 mm; tips green; surfaces densely floccose-tomentose.
Calyculi	0 or 1–5+ linear to filiform bractlets, 2–3 mm.	1–5+ linear bractlets; to 2 mm.
Fruits	1.5–2.5 mm, sparsely pubescent on ribs.	2–3 mm, usually hairy along the ribs, sometimes glabrous.
Heads	12–24.	6–10(20).
2n	=40.	=40.

	Senecio sylvaticus	Senecio ertterae
Distribution	[WildflowerSearch map] [BONAP county 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.	Talus slopes, volcanic tuff. Flowering May–Sep. 800–1400 m. Owy. Native. Endemic to Oregon. This species was not recognized until the late 1970s. It is a very rare endemic found only in Malheur County. It has been added to the Center for Plant Conservation’s National Collection of Endangered Plants.
Source	Flora of Oregon, volume 2, page 341 Debra Trock	Flora of Oregon, volume 2, page 338 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. 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: OR Local Web sites: 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 ertterae

wood groundsel, woodland ragwort

Ertter's groundsel

Habit

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

Herbs annual, 2–5(6+) dm; taproots twisting, thin.

Stems

1, densely pubescent with abundant curly hairs.

usually 1, rarely clustered, subsucculent, unevenly tomentose to glabrate.

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.

basal withering early;

cauline oblanceolate to spatulate, bases tapering;

margins deeply incised;

petioles winged;

distal sessile and bract-like, progressively reduced.

Inflorescences

corymb-like arrays;

bracts 0 or inconspicuous.

cyme-like arrays;

bracts 0 or few and inconspicuous.

Involucres

cylindric.

widely cylindric.

Ray florets

0, rarely 1–8;

rays 1–2+ mm.

8, rarely 13;

rays 5–6 mm.

Disc florets

40–50.

45–55.

Phyllaries

13+, rarely 21, 4–7+ mm;

tips green or minutely black.

usually 13, 6–7 mm;

tips green;

surfaces densely floccose-tomentose.

Calyculi

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

1–5+ linear bractlets; to 2 mm.

Fruits

1.5–2.5 mm, sparsely pubescent on ribs.

2–3 mm, usually hairy along the ribs, sometimes glabrous.

Heads

12–24.

6–10(20).

=40.

Senecio ertterae

Distribution

[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.

Talus slopes, volcanic tuff. Flowering May–Sep. 800–1400 m. Owy. Native. Endemic to Oregon.

This species was not recognized until the late 1970s. It is a very rare endemic found only in Malheur County. It has been added to the Center for Plant Conservation’s National Collection of Endangered Plants.

Source

Flora of Oregon, volume 2, page 341
Debra Trock

Flora of Oregon, volume 2, page 338
Debra Trock

Sibling taxa