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cleft-leaf groundsel, Rocky Mountain butterweed, Rocky Mountain groundsel

threetooth ragwort

Habit Perennials, 10–50+ cm; fibrous-rooted (caudices weak to stout, horizontal to suberect). Perennials, 10–30+ cm; taprooted (caudices ascending to erect).
Stems

1 or 2–5, clustered, usually glabrous, sometimes sparsely floccose-tomentose proximally and in leaf axils.

1 or multiple, clustered, usually glabrous, rarely sparsely floccose-tomentose, leaf axils sometimes tomentose.

Basal leaves

(and proximal cauline, relatively thick and turgid) petiolate;

blades spatulate to oblanceolate, or ovate to orbiculate, 20–40+ × 10–30+ mm, bases tapering to abruptly contracted or subcordate, margins entire, crenate, dentate, or weakly lobulate (faces usually glabrous, sometimes hairy).

(and proximal cauline, relatively thick and turgid) petiolate;

blades lanceolate or narrowly oblanceolate, 20–40+ × 5–15 mm, bases tapering, margins usually entire, sometimes sub-pinnatisect (apices subentire or dentate).

Cauline leaves

gradually to abruptly reduced (± petiolate or sessile; entire or subentire).

gradually reduced (± petiolate or sessile).

Peduncles

bracteate, glabrous or sparsely tomentose.

bracteate, glabrous or sparsely tomentose.

Ray florets

8 or 13;

corolla laminae 5–10 mm.

8–10(–13);

corolla laminae 5–8+ mm.

Disc florets

35–60+;

corolla tubes 2–4 mm, limbs 2.5–4 mm.

45–60+;

corolla tubes 3–3.5 mm, limbs 4–5 mm.

Phyllaries

(8–)13 or 21, green (tips sometimes cyanic), 4–7+ mm, glabrous.

13 or 21, green, 6–10 mm, sparsely tomentose proximally, glabrous distally.

Calyculi

conspicuous.

inconspicuous.

Heads

2–20+ in loose, corymbiform or subumbelliform arrays.

4–15+ in corymbiform arrays.

Cypselae

1–2.5 mm, glabrous;

pappi 3–6 mm.

1.5–2.5 mm, glabrous or sparsely hirtellous on ribs;

pappi 5–6 mm.

2n

= 46, 92.

= 46.

Packera streptanthifolia

Packera tridenticulata

Phenology Flowering late May–late Aug. Flowering late May–early Jul.
Habitat Forests, open meadows, valleys, dry to damp and loamy soils Open, dry areas, roadsides, gravelly or sandy slopes, short-grass prairies or sagebrush scrubs
Elevation 1000–3400 m (3300–11200 ft) 1000–2000 m (3300–6600 ft)
Distribution
from FNA
CA; CO; ID; MT; NM; NV; OR; UT; WA; WY; AB; BC; NT; SK; YT
[WildflowerSearch map]
[BONAP county map]
from FNA
CO; KS; ND; NE; NM; OK; SD; TX; WY
[WildflowerSearch map]
Discussion

Packera streptanthifolia is widespread and variable throughout the Western Cordillera. It includes weakly defined phases that have been treated as distinct species or as varieties. Characteristics used to delimit those taxa often overlap and are difficult to score; some “phases” grade into each other. Northern populations are sometimes segregated as a distinct taxon (e.g., Senecio streptanthifolia var. borealis; J. F. Bain 1988).

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Packera tridenticulata is found throughout the central High Plains, in the foothills of the Rocky Mountains, and in high valleys to the west of the Rocky Mountain front. It tends to grow in clumps; the multiple stems arise from well-developed taproots. It apparently hybridizes with P. neomexicana var. mutabilis where their ranges overlap.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 20, p. 599. FNA vol. 20, p. 601.
Parent taxa Asteraceae > tribe Senecioneae > Packera Asteraceae > tribe Senecioneae > Packera
Sibling taxa
P. anonyma, P. antennariifolia, P. aurea, P. bernardina, P. bolanderi, P. breweri, P. cana, P. cardamine, P. castoreus, P. clevelandii, P. contermina, P. crocata, P. cymbalaria, P. cynthioides, P. debilis, P. dimorphophylla, P. eurycephala, P. fendleri, P. flettii, P. franciscana, P. ganderi, P. glabella, P. greenei, P. hartiana, P. hesperia, P. hyperborealis, P. indecora, P. ionophylla, P. layneae, P. macounii, P. malmstenii, P. millefolium, P. millelobata, P. multilobata, P. musiniensis, P. neomexicana, P. obovata, P. ogotorukensis, P. pauciflora, P. paupercula, P. plattensis, P. porteri, P. pseudaurea, P. quercetorum, P. sanguisorboides, P. schweinitziana, P. spellenbergii, P. subnuda, P. tampicana, P. texensis, P. tomentosa, P. tridenticulata, P. werneriifolia
P. anonyma, P. antennariifolia, P. aurea, P. bernardina, P. bolanderi, P. breweri, P. cana, P. cardamine, P. castoreus, P. clevelandii, P. contermina, P. crocata, P. cymbalaria, P. cynthioides, P. debilis, P. dimorphophylla, P. eurycephala, P. fendleri, P. flettii, P. franciscana, P. ganderi, P. glabella, P. greenei, P. hartiana, P. hesperia, P. hyperborealis, P. indecora, P. ionophylla, P. layneae, P. macounii, P. malmstenii, P. millefolium, P. millelobata, P. multilobata, P. musiniensis, P. neomexicana, P. obovata, P. ogotorukensis, P. pauciflora, P. paupercula, P. plattensis, P. porteri, P. pseudaurea, P. quercetorum, P. sanguisorboides, P. schweinitziana, P. spellenbergii, P. streptanthifolia, P. subnuda, P. tampicana, P. texensis, P. tomentosa, P. werneriifolia
Synonyms Senecio streptanthifolius, P. streptanthifolia var. borealis, Senecio adamsii, Senecio aureus var. borealis, Senecio cognatus, Senecio cymbalarioides, Senecio cymbalarioides var. borealis, Senecio cymbalarioides var. streptanthifolius, Senecio fulgens, Senecio jonesii, Senecio leonardii, Senecio longipetiolatus, Senecio oödes, Senecio platylobus, Senecio rydbergii, Senecio streptanthifolius var. borealis, Senecio streptanthifolius var. kluanei, Senecio streptanthifolius var. laetiflorus, Senecio streptanthifolius var. oödes, Senecio streptanthifolius var. rubricaulis, Senecio streptanthifolius var. wallowensis, Senecio subcuneatus, Senecio suksdorfii, Senecio wardii Senecio tridenticulatus, Senecio acutidens, Senecio compactus, Senecio densus, Senecio oblanceolatus
Name authority (Greene) W. A. Weber & Á. Löve: Phytologia 49: 48. (1981) (Rydberg) W. A. Weber & Á. Löve: Phytologia 49: 48. (1981)
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