Burke: Senecio integerrimus vs. Senecio hydrophiloides

	Senecio integerrimus	Senecio hydrophiloides
	one-stemmed butterweed, western groundsel	sweet marsh butterweed, stout meadow groundsel
Habit	Stout, fibrous-rooted perennial from a very short crown; stems solitary, 2-7 dm. tall; plants covered with white, loose hairs when young, but these missing in older plants except in the leaf axils.	Glabrous but scarcely glaucous, fibrous-rooted perennial from a short crown, 3-10 dm. tall, the stems solitary or more commonly clustered.
Leaves	Usually entire, elliptic to broadly lanceolate, the basal ones petiolate, the blade and petiole 6-25 cm. long and 1-6 cm wide; cauline leaves progressively reduced upward, becoming sessile toward the top of the stem.	Somewhat succulent, sharply dentate, the basal and lowermost cauline ones petiolate, with elliptic or broadly oblanceolate blades 6-25 cm. long and 2-7 cm. wide; upper leaves few, strongly reduced, becoming sessile toward the upper stem.
Flowers	Heads several to numerous in a rather congested inflorescence; involucre 5-10 mm. long; rays 6-15 mm. long, usually yellow, occasionally cream.	Heads fairly numerous in a congested inflorescence; involucre 6-9 mm. high, the bracts often black-tipped; rays typically about 5, up to about 8 mm. long, frequently wanting.

	Senecio integerrimus	Senecio hydrophiloides
Identification notes	A Senecio growing on dry ground, with a fairly tall, single, upright stem and large, entire leaves is probably this species, especially if the leaves are lightly covered with white, tangled hairs.
Flowering time	May-August	May-July
Habitat	Meadows and seasonally moist open areas from low elevations to the subalpine.	Wet meadows in the mountains and foothills, but not in alkali.
Distribution	Occurring chiefly east of the Cascades crest in Washington, where widely distributed; British Columbia to California, east to the Great Plains and Great Lakes region. [WildflowerSearch map] [BONAP county map]	Occurring east of the Cascades crest in Washington; British Columbia to California, east to Alberta, Montana, Wyoming, and Utah. [WildflowerSearch map] [BONAP county map]
Origin	Native	Native
Conservation status	Not of concern	Not of concern
Sibling taxa	S. elmeri, S. fremontii, S. hydrophiloides, S. hydrophilus, S. lugens, S. neowebsteri, S. serra, S. sylvaticus, S. triangularis, S. viscosus, S. vulgaris	S. elmeri, S. fremontii, S. hydrophilus, S. integerrimus, S. lugens, S. neowebsteri, S. serra, S. sylvaticus, S. triangularis, S. viscosus, S. vulgaris
Subordinate taxa	S. integerrimus var. exaltatus, S. integerrimus var. ochroleucus
Web links	Local floras: BC, CA, OR, WA Local Web sites: CalFlora, CalPhotos, 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	Local floras: BC, CA, OR, WA Local Web sites: CalFlora, CalPhotos, 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 hydrophiloides

one-stemmed butterweed, western groundsel

sweet marsh butterweed, stout meadow groundsel

Habit

Stout, fibrous-rooted perennial from a very short crown; stems solitary, 2-7 dm. tall; plants covered with white, loose hairs when young, but these missing in older plants except in the leaf axils.

Glabrous but scarcely glaucous, fibrous-rooted perennial from a short crown, 3-10 dm. tall, the stems solitary or more commonly clustered.

Leaves

Usually entire, elliptic to broadly lanceolate, the basal ones petiolate, the blade and petiole 6-25 cm. long and 1-6 cm wide;

cauline leaves progressively reduced upward, becoming sessile toward the top of the stem.

Somewhat succulent, sharply dentate, the basal and lowermost cauline ones petiolate, with elliptic or broadly oblanceolate blades 6-25 cm. long and 2-7 cm. wide; upper leaves few, strongly reduced, becoming sessile toward the upper stem.

Flowers

Heads several to numerous in a rather congested inflorescence;

involucre 5-10 mm. long;

rays 6-15 mm. long, usually yellow, occasionally cream.

Heads fairly numerous in a congested inflorescence;

involucre 6-9 mm. high, the bracts often black-tipped;

rays typically about 5, up to about 8 mm. long, frequently wanting.

Senecio integerrimus

Senecio hydrophiloides

Identification notes

A Senecio growing on dry ground, with a fairly tall, single, upright stem and large, entire leaves is probably this species, especially if the leaves are lightly covered with white, tangled hairs.

Flowering time

May-August

May-July

Habitat

Meadows and seasonally moist open areas from low elevations to the subalpine.

Wet meadows in the mountains and foothills, but not in alkali.

Distribution

Occurring chiefly east of the Cascades crest in Washington, where widely distributed; British Columbia to California, east to the Great Plains and Great Lakes region.

[WildflowerSearch map]

[BONAP county map]