OregonFlora: Packera streptanthifolia vs. Packera porteri

	Packera streptanthifolia	Packera porteri
	cleftleaf groundsel, Rocky Mountain butterweed, Rocky Mountain groundsel	Porter's butterweed, Porter's groundsel
Habit	Plants perennial, 20–50+ cm; caudices weak or stout, horizontal or suberect and fibrous-rooted.	Plants perennial, 3–10+ cm; caudices with fleshy, branching rhizomes.
Stems	1 or 2–5, clustered, glabrous or sometimes sparsely pubescent near base and in leaf axils.	1, glabrous.
Basal leaves	blades oblanceolate to orbiculate; thick; turgid, bases tapering to contracted; margins dentate, dissected; entire, subentire or weakly lobulate; surfaces usually glabrous, sometimes pubescent, petiolate.	blades reniform to subreniform, relatively turgid, bases abruptly contracted to cordate; margins crenate, sometimes wavy, abaxially cyanic, petiolate.
Cauline leaves	similar to basal, gradually reduced, petiolate or sessile.	bract-like; margins entire.
Involucres	campanulate.	campanulate; bractlets often cyanic.
Ray florets	8 or 13; rays 5–10 mm.	8 or 13; rays 8–10+ mm.
Disc florets	35–60; corolla tubes 2–4 mm; limbs 2.5–4 mm.	40–50+; corolla tubes 2.5–3.5 mm; limbs 2.5–3.5 mm.
Phyllaries	(8)13 or 21, 4–7+ mm, green; tips sometimes anthocyanic; surfaces glabrous.	13 or 21, 8–10+ mm; deep red; surfaces glabrous.
Calyculi	conspicuous.	conspicuous.
Fruit(s)	1–2.5 mm, glabrous; pappi 3–6 mm.	1.5–2.5 mm, glabrous; pappi 4–5.5 mm.
Heads	2–20+; in corymb- or subumbel-like arrays; peduncles glabrous or sparsely tomentose, bracteate.	1; peduncles glabrous; bracts absent.
2n	=46, 92.

	Packera streptanthifolia	Packera porteri
Distribution	[WildflowerSearch map] [BONAP county map]	[BONAP county map]
Discussion	Forests, open meadows, and valleys in dry to damp loamy soils. Flowering May–Aug. 400–2900 m. BR, BW, ECas, Lava, Owy, Sisk. ID, NV, WA; north to Yukon, northeast to Saskatchewan, east to WY, southeast to NM. Native. Packera streptanthifolia includes weakly defined “phases” that have been treated as distinct species or as varieties. Characteristics used to define those taxa often overlap and are difficult to distinguish; some phases grade into each other.	Steep, alpine talus slopes. Flowering Jul–Aug. 2100–2500 m. BW. WA; CO. Native. Only a single collection locality for Packera porteri is known from Oregon. In August of 1899, W.C. Cusick collected several duplicates of this species from “alpine ridges of the Wallowa Mountains, near the lake.” He noted at the time that “few plants were seen.” It has not been collected there since, although there is one additional observation from 1978. This species is more frequently collected (although still rare) on high peaks in the Rocky Mountains of central Colorado, nearly always being collected at over 3,600 m. Packera porteri is likely infrequently collected because it occurs only on steep talus slopes, using extensive fleshy rhizomes to find purchase in a precarious habitat. In this author’s opinion, it is one of the most interesting and elusive species in the genus and certainly worthy of concerted efforts to determine its current conservation status.
Source	Flora of Oregon, volume 2, page 324 Debra Trock	Flora of Oregon, volume 2, page 323 Debra Trock
Sibling taxa	P. bolanderi, P. cana, P. eurycephala, P. flettii, P. hesperia, P. macounii, P. porteri, P. pseudaurea, P. subnuda	P. bolanderi, P. cana, P. eurycephala, P. flettii, P. hesperia, P. macounii, P. pseudaurea, P. streptanthifolia, P. subnuda
Synonyms	Packera streptanthifolia var. streptanthifolia, Senecio cymbalarioides, Senecio leonardii, Senecio streptanthifolius	Senecio porteri
Web links	Local floras: BC, 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	Local floras: OR, WA 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

Packera porteri

cleftleaf groundsel, Rocky Mountain butterweed, Rocky Mountain groundsel

Porter's butterweed, Porter's groundsel

Habit

Plants perennial, 20–50+ cm; caudices weak or stout, horizontal or suberect and fibrous-rooted.

Plants perennial, 3–10+ cm; caudices with fleshy, branching rhizomes.

Stems

1 or 2–5, clustered, glabrous or sometimes sparsely pubescent near base and in leaf axils.

1, glabrous.

Basal leaves

blades oblanceolate to orbiculate; thick; turgid, bases tapering to contracted;

margins dentate, dissected; entire, subentire or weakly lobulate;

surfaces usually glabrous, sometimes pubescent, petiolate.

blades reniform to subreniform, relatively turgid, bases abruptly contracted to cordate;

margins crenate, sometimes wavy, abaxially cyanic, petiolate.

Cauline leaves

similar to basal, gradually reduced, petiolate or sessile.

bract-like;

margins entire.

Involucres

campanulate.

campanulate;

bractlets often cyanic.

Ray florets

8 or 13;

rays 5–10 mm.

8 or 13;

rays 8–10+ mm.

Disc florets

35–60;

corolla tubes 2–4 mm;

limbs 2.5–4 mm.

40–50+;

corolla tubes 2.5–3.5 mm;

limbs 2.5–3.5 mm.

Phyllaries

(8)13 or 21, 4–7+ mm, green;

tips sometimes anthocyanic;

surfaces glabrous.

13 or 21, 8–10+ mm; deep red;

surfaces glabrous.

Calyculi

conspicuous.

Fruit(s)

1–2.5 mm, glabrous;

pappi 3–6 mm.

1.5–2.5 mm, glabrous;

pappi 4–5.5 mm.

Heads

2–20+; in corymb- or subumbel-like arrays;

peduncles glabrous or sparsely tomentose, bracteate.

peduncles glabrous;

bracts absent.

=46, 92.

Packera porteri

Distribution

[WildflowerSearch map]

[BONAP county map]

Discussion

Forests, open meadows, and valleys in dry to damp loamy soils. Flowering May–Aug. 400–2900 m. BR, BW, ECas, Lava, Owy, Sisk. ID, NV, WA; north to Yukon, northeast to Saskatchewan, east to WY, southeast to NM. Native.

Packera streptanthifolia includes weakly defined “phases” that have been treated as distinct species or as varieties. Characteristics used to define those taxa often overlap and are difficult to distinguish; some phases grade into each other.

Steep, alpine talus slopes. Flowering Jul–Aug. 2100–2500 m. BW. WA; CO. Native.

Only a single collection locality for Packera porteri is known from Oregon. In August of 1899, W.C. Cusick collected several duplicates of this species from “alpine ridges of the Wallowa Mountains, near the lake.” He noted at the time that “few plants were seen.” It has not been collected there since, although there is one additional observation from 1978. This species is more frequently collected (although still rare) on high peaks in the Rocky Mountains of central Colorado, nearly always being collected at over 3,600 m. Packera porteri is likely infrequently collected because it occurs only on steep talus slopes, using extensive fleshy rhizomes to find purchase in a precarious habitat. In this author’s opinion, it is one of the most interesting and elusive species in the genus and certainly worthy of concerted efforts to determine its current conservation status.

Source

Flora of Oregon, volume 2, page 324
Debra Trock

Flora of Oregon, volume 2, page 323
Debra Trock

Sibling taxa