|
| Packera plattensis
(Nutt.) W.A. Weber & A. Löve |
|
| |
| TAXONOMY |
| |
| Family: |
Asteraceae or Compositae |
| Genus: |
Packera |
| |
| Species Synonyms: |
Senecio pseudotomentosus Mackenzie &
Bush
Senecio plattensis Nutt. |
| Common Names: |
prairie groundsel |
| |
| DISTRIBUTION |
| |
| 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 |
| |
| HABITAT |
| |
| Saskatchewan: |
grasslands, sloughs, shores and open woods |
| Associated Species: |
agoseris, hawksbeard, trembling aspen |
| |
| RARITY STATUS |
| |
Provincial
Status According
to Harms (2003): |
Threatened |
| Nature Conservancy
Status: |
G5 S3S4 |
Saskatchewan
Species at
Risk Status: |
None |
| COSEWIC Status:
|
None |
| |
| 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. |
| |
| SPECIES
DESCRIPTION |
| |
| 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 |
| |
| KEY TO PACKERA
IN SASKATCHEWAN |
| 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 |
2 |
| 1 Plants usually woolly-hairy (sometime
glabrous) and/ or with basal leaves; basal leaves if present pinnately lobed
or dissected |
8 |
| |
|
2 Ray flowers 0 or 8 – 13 (petals
2 – 7 mm long); plants of northern Saskatchewan
|
3 |
| 2 Ray flowers 0 or 5 – 21 (petals
4 – 12 mm long); plants from various areas of Saskatchewan |
4 |
| |
|
| 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 |
5 |
| 4 Basal and lower stem leaves gradually
tapering to stalk |
6 |
| |
|
| 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 |
| |
|
| 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 |
| |
|
| 9 Plants 3 – 10 cm tall; heads
few (1-6) |
P. cana |
| 9 Plants 10 – 50 cm tall; heads
several (6 – 30) |
10 |
| |
|
| 10 Basal leaves nearly circular to
broadly oval |
11 |
| 10 Basal leaves narrowly elliptic
to spoon-shaped |
12 |
| |
|
| 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 |
|
