Packera plattensis (Nutt.) W.A. Weber & A. Löve
Species Image Gallery
(opens in a new window)
Family: Asteraceae or Compositae
Genus: Packera
Species Synonyms: Senecio pseudotomentosus Mackenzie & Bush
Senecio plattensis Nutt.
Common Names: prairie groundsel
Canada: Mackenzie District – British Columbia – Ontario
Saskatchewan: widespread; Lake Athabasca – Cypress Hills
Ecoregion: Cypress Upland, Moist Mixed Grassland, Aspen Parkland, Boreal Transition, Mid-Boreal Lowland, Mid-Boreal Upland, Churchill River Upland, Tazin Lake Upland
Saskatchewan: grasslands, sloughs, shores and open woods
Associated Species: agoseris, hawksbeard, trembling aspen
Provincial Status According
to Harms (2003):
Nature Conservancy Status:
G5 S3S4
Saskatchewan Species at
Risk Status:
Prairie groundsel is threatened; however this complex needs taxonomic revision. Most specimens of prairie groundsel in Saskatchewan have been re-identified as balsam groundsel and it is unclear where this species really exists. No threats are known or anticipated for prairie groundsel at this time.
Roots: fibrous; sometimes with runners
Stems: stem base short, ascending, persistent, woody; stems solitary, rarely 2 – 3, lightly covered in long, tangled, woolly hairs or irregularly hairless
Leaves: basal and on the stem; basal leaves several, tufted, stalk slender, elliptic-oval to inversely lance-shaped, toothed to pinnately lobed; stem leaves reduced upwards, linear, grey-woolly, uppermost leaves irregularly dissected to subentire
Inflorescence: heads 6 – 20; stalks densely woolly; bracts linear, purple-tipped
Flowers: ray flowers 6 – 10, 8 – 12 mm long
Fruits: achenes pubescent with small, stiff, straight hairs, occasionally hairless
Note: This complex needs taxonomic revision. The key may not be accurate in all cases. Please refer to another key if you encounter difficulty with this one.
1 Plants usually hairless or nearly so; basal leaves usually entire or toothed, not lobed
1 Plants usually woolly-hairy (sometime glabrous) and/ or with basal leaves; basal leaves if present pinnately lobed or dissected
2 Ray flowers 0 or 8 – 13 (petals 2 – 7 mm long); plants of northern Saskatchewan
2 Ray flowers 0 or 5 – 21 (petals 4 – 12 mm long); plants from various areas of Saskatchewan
3 Basal leaves thick; heads few (1 – 4); bracts purple or at least purple-tipped
P. pauciflora
3 Basal leaves thin; head numerous (8 – 20); bracts green
P. indecora
4 Basal and lower stem leaves not tapering to stalk, base square to heart-shaped
4 Basal and lower stem leaves gradually tapering to stalk
5 Basal leaves lance-shaped to narrowly oval, tip short-tapered; margin toothed
P. pseudaurea
5 Basal leaves heart-shaped, spoon-shaped, or oval, tip rounded; margin toothed, lobed or wavy
P. streptanthifolia
6 Plants with a taproots and woody persistent stem base; may be woolly in leaf axils
P. tridenticulata
6 Plants with fibrous, taproots or rhizomes, persistent stem base if present not woody; leaves and stems generally all hairless
7 Basal leaves thick, inversely lance-shaped to spatula-shaped; disc flowers 35 – 60
P. streptanthifolia
7 Basal leaves thin, lance-shaped to elliptic; disc flowers 50 – 80
P. paupercula
8 Stems and leaves persistently woolly
P. plattensis
8 Stems and leaves usually hairless, sometimes woolly at base or in leaf axils
9 Plants 3 – 10 cm tall; heads few (1-6)
P. cana
9 Plants 10 – 50 cm tall; heads several (6 – 30)
10 Basal leaves nearly circular to broadly oval
10 Basal leaves narrowly elliptic to spoon-shaped
11 Margins of basal leaves entire to toothed; bracts hairless
P. streptanthifolia
11 Margins of basal leaves toothed to divided; bracts densely woolly
P. plattensis
12 Basal leaves toothed to lobed; tangled woolly to nearly hairless
P. plattensis
12 Basal leaves entire, except towards toothed tip; white woolly
P. cana