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threetooth ragwort

Habit Perennials, 10–30+ cm; taprooted (caudices ascending to erect). Perennials, 5–10 cm; ± rhizomatous (bases loosely branched, elongated, horizontal to ascending).
Stems

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

1 (sometimes branched from bases), densely white- or gray-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 oblanceolate, 20–30+ × 5–13+ mm, bases tapering, margins pinnatifid to crenate.

Cauline leaves

gradually reduced (± petiolate or sessile).

gradually reduced (sessile; proximal and mid nearly equaling basals, distals bractlike).

Peduncles

bracteate, glabrous or sparsely tomentose.

ebracteate, tomentose.

Ray florets

8–10(–13);

corolla laminae 5–8+ mm.

0 or 1;

corolla laminae ca. 6 mm.

Disc florets

45–60+;

corolla tubes 3–3.5 mm, limbs 4–5 mm.

not seen.

Phyllaries

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

8–13, yellow-green to purple (or with purplish midstripes), 8–9.5 mm, sparsely tomentose (apices rounded).

Calyculi

inconspicuous.

0 or inconspicuous.

Heads

4–15+ in corymbiform arrays.

3–15+ in corymbiform arrays.

Cypselae

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

pappi 5–6 mm.

not seen (reported to be glabrous).

2n

= 46.

= 46.

Packera tridenticulata

Packera musiniensis

Phenology Flowering late May–early Jul. Flowering mid Jul–mid Aug.
Habitat Open, dry areas, roadsides, gravelly or sandy slopes, short-grass prairies or sagebrush scrubs Subalpine and alpine ridges, talus or scree slopes, barren areas on Flagstaff limestone
Elevation 1000–2000 m (3300–6600 ft) 2900–3300 m (9500–10800 ft)
Distribution
from FNA
CO; KS; ND; NE; NM; OK; SD; TX; WY
[WildflowerSearch map]
from FNA
UT
[BONAP county 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.)

Of conservation concern.

Packera musiniensis is a high-elevation dwarf species; its affinities within Packera are still uncertain. Welsh believed it to be allied to P. cana or P. multilobata, or both.

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

Source FNA vol. 20, p. 601. FNA vol. 20, p. 592.
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. 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. 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 musiniensis
Name authority (Rydberg) W. A. Weber & Á. Löve: Phytologia 49: 48. (1981) (S. L. Welsh) Trock: Sida 21: 1643. (2005)
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