Burke: Senecio integerrimus vs. Senecio neowebsteri

	Senecio integerrimus	Senecio neowebsteri
	one-stemmed butterweed, western groundsel	Olympic Mountain ragwort
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.	Perennial from a well-developed rhizome, the stem 0.5-2 dm. tall; herbage spider-webby at first, becoming nearly glabrous.
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.	Basal leaves large, petiolate, sometimes tufted on separate short shoots, the blade broadly oblanceolate to sub-rotund, up to 7 cm. long a 4 cm. wide; cauline leaves few, usually strongly reduced; leaves often with purplish margins.
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 solitary, nodding, the involucre 11-17 mm. high, the disk 1.5-2.5 cm. wide; involucre bracts in a single series, equal, herbaceous, the tips pale; ray flowers yellow, pistillate and fertile, the rays 10-15 mm. long; disk flowers yellow, perfect and fertile; pappus of white capillary bristles.
Fruits		Achene sub-terete

	Senecio integerrimus	Senecio neowebsteri
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	Aug.-Sept.
Habitat	Meadows and seasonally moist open areas from low elevations to the subalpine.	Talus slopes and rocky places.
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 west of the Cascades crest, where endemic to the Olympic Mountains of Washington. [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. hydrophiloides, S. hydrophilus, S. integerrimus, S. lugens, 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: 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 integerrimus

Senecio neowebsteri

one-stemmed butterweed, western groundsel

Olympic Mountain ragwort

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.

Perennial from a well-developed rhizome, the stem 0.5-2 dm. tall; herbage spider-webby at first, becoming nearly glabrous.

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.

Basal leaves large, petiolate, sometimes tufted on separate short shoots, the blade broadly oblanceolate to sub-rotund, up to 7 cm. long a 4 cm. wide;

cauline leaves few, usually strongly reduced;

leaves often with purplish margins.

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 solitary, nodding, the involucre 11-17 mm. high, the disk 1.5-2.5 cm. wide;

involucre bracts in a single series, equal, herbaceous, the tips pale;

ray flowers yellow, pistillate and fertile, the rays 10-15 mm. long;

disk flowers yellow, perfect and fertile;

pappus of white capillary bristles.

Fruits

Achene sub-terete

Senecio integerrimus

Senecio neowebsteri

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

Aug.-Sept.

Habitat

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

Talus slopes and rocky places.

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]