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threetooth ragwort

dwarf arctic groundsel, dwarf arctic ragwort, northern butterweed

Habit Perennials, 10–30+ cm; taprooted (caudices ascending to erect). Perennials, 6–25+ cm; rhizomatous (mat forming, rhizomes horizontal to suberect, branched).
Stems

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

usually 1 (sometimes more, clustered), usually glabrous, sometimes bases and leaf axils tomentose.

Basal leaves

(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).

petiolate;

blades ovate to obovate, lyrate, or reniform, 10–30+ × 10–25+ mm, bases cuneate (sometimes tapering to winged petioles) to subcordate or contracted, margins crenate, dentate, or weakly lobed.

Cauline leaves

gradually reduced (± petiolate or sessile).

abruptly reduced (sessile, not clasping; lanceolate, entire or pinnately lobed to pinnatisect).

Peduncles

bracteate, glabrous or sparsely tomentose.

0 or relatively reduced (then densely tomentose).

Ray florets

8–10(–13);

corolla laminae 5–8+ mm.

0 or 11–13;

corolla laminae (yellow, purple streaks in veins) 10–14+ mm.

Disc florets

45–60+;

corolla tubes 3–3.5 mm, limbs 4–5 mm.

60–75+;

corolla tubes 2–2.5 mm, limbs 4–5 mm.

Phyllaries

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

21, deep red or green (tips red), 6–8 mm, glabrous.

Calyculi

inconspicuous.

conspicuous (bractlets cyanic).

Heads

4–15+ in corymbiform arrays.

1–2.

Cypselae

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

pappi 5–6 mm.

1.5–2 mm, glabrous;

pappi 5–6 mm.

2n

= 46.

= 46, 92, 138.

Packera tridenticulata

Packera cymbalaria

Phenology Flowering late May–early Jul. Flowering mid Jun–early Aug.
Habitat Open, dry areas, roadsides, gravelly or sandy slopes, short-grass prairies or sagebrush scrubs Exposed rocky slopes, tundra turf
Elevation 1000–2000 m (3300–6600 ft) 0–1900 m (0–6200 ft)
Distribution
from FNA
CO; KS; ND; NE; NM; OK; SD; TX; WY
[WildflowerSearch map]
from FNA
AK; AB; BC; NF; NT; QC; YT
[WildflowerSearch map]
Discussion

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.)

Packera cymbalaria occurs in three, disjunct regions: western Alaska eastward into western N.W.T. and south into northwestern British Columbia; Newfoundland and the Gaspé Peninsula, Quebec; and Siberia. Considerable morphologic overlap exists between western and eastern populations in North America; western populations have slightly different flavonoid chemistries and chromosome numbers. Western populations are either diploid or tetraploid; eastern populations are hexaploid. The correct name for this species may prove to be Packera heterophylla (Fischer) E. Wiebe, based on Cineraria heterophylla Fischer.

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

Source FNA vol. 20, p. 601. FNA vol. 20, p. 583.
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. streptanthifolia, P. subnuda, P. tampicana, P. texensis, P. tomentosa, 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. 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. tridenticulata, P. werneriifolia
Synonyms Senecio tridenticulatus, Senecio acutidens, Senecio compactus, Senecio densus, Senecio oblanceolatus Senecio cymbalaria, Cineraria lyrata, P. resedifolia, S. fernaldii, S. resedifolius
Name authority (Rydberg) W. A. Weber & Á. Löve: Phytologia 49: 48. (1981) (Pursh) W. A. Weber & Á. Löve: Bot. Not. 128: 497. (1976)
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