Packera paupercula
Packera castoreus
balsam groundsel, Canadian butterweed
beaver mountain ragwort
1 or 2–4, loosely clustered, glabrous or sparsely tomentose proximally.
1 or 2–3, (white) woolly-tomentose.
petiolate;
blades lanceolate to narrowly elliptic or oblanceolate, 30–60+ × 10–20+ mm, bases tapering, sometimes obtuse, margins subentire to dentate or serrate.
(and proximal cauline) petiolate;
blades obovate to oblanceolate or spatulate, 10–20+ × 5–18 mm, bases tapering, margins entire or crenate (abaxial faces densely tomentose, adaxial glabrescent).
gradually reduced (proximals petiolate, sublyrate; mids sessile, not clasping, lanceolate, dissected, incised, or lacerate; distals sessile, bractlike).
gradually reduced (becoming sessile and bractlike).
usually bracteate, sometimes ebracteate, glabrous.
ebracteate.
0, 8, or 13;
corolla laminae (pale yellow) 5–10+ mm.
0.
50–65+;
corolla tubes 2–3 mm, limbs 2–3 mm.
not seen.
13 or 21, green, 5–8+ mm, glabrous.
purple-tinged, 7–10 mm, tomentose (ciliate distally, apices with dense tufts of hairs).
inconspicuous.
inconspicuous.
2–10+ in loose or compact, corymbiform arrays.
1–4+, in corymbiform arrays.
1–2 mm, usually glabrous, sometimes hispidulous on ribs;
pappi 3.5–4.5 mm.
not seen (reported to be glabrous).
= 44, 46, 92.
Packera paupercula
Packera castoreus
Ecologically and morphologically, Packera paupercula is the most variable species of the genus in North America. Some “phases” have been treated as separate species, subspecies, varieties, forms, and races. Variation within P. paupercula hints at some interesting evolutionary relationships; characteristics used to separate taxa overlap. Much of the morphologic variation in this species may be due to hybridization and introgression. I do not recognize any of the infraspecific taxa that have been proposed.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Of conservation concern.
Packera castoreus is known only from relatively few collections from the Tushar Mountains in Beaver and Piute counties. Welsh speculated that it may have some affinities with P. cana and P. werneriifolia.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
- Local floras:
BC, 
WA - Local Web sites:
Flora NW, 
Go Botany, 
IL Wildflowers, 
MD Biodiversity, 
MI Flora, 
MN Wildflowers, 
PNW Herbaria 
WildflowerSearch
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USDA Plants Database- LBJ Wildflower Center
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