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threetooth ragwort

Uinta ragwort

Habit Perennials, 10–30+ cm; taprooted (caudices ascending to erect). Perennials, 30–50+ cm; taprooted or ± rhizomatous (bases weakly creeping, horizontal to erect).
Stems

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

1 or 2–5+, loosely clustered, glabrous or leaf axils sparsely 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).

(and proximal cauline) petiolate;

blades narrowly lanceolate (pinnatifid, lateral lobes 6+ pairs, their bases petioluliform, terminal lobes smaller than laterals), 60–100 × 10–20 mm, bases tapering, ultimate margins dentate.

Cauline leaves

gradually reduced (± petiolate or sessile).

gradually reduced (sessile).

Peduncles

bracteate, glabrous or sparsely tomentose.

bracteate or ebracteate, glabrous.

Ray florets

8–10(–13);

corolla laminae 5–8+ mm.

(8–)13;

corolla laminae 8–10+ mm.

Disc florets

45–60+;

corolla tubes 3–3.5 mm, limbs 4–5 mm.

40–55+;

corolla tubes 2–3 mm, limbs 2–3 mm.

Phyllaries

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

(13–)21, green (tips yellow), 4–6+ mm, glabrous.

Calyculi

inconspicuous.

inconspicuous.

Heads

4–15+ in corymbiform arrays.

6–20+ in corymbiform arrays.

Cypselae

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

pappi 5–6 mm.

1–1.5 mm, hirtellous on ribs;

pappi 3.5–4.5 mm.

2n

= 46.

Packera tridenticulata

Packera millelobata

Phenology Flowering late May–early Jul. Flowering late Mar–early Jun.
Habitat Open, dry areas, roadsides, gravelly or sandy slopes, short-grass prairies or sagebrush scrubs Streambeds, openings in wooded areas on limestone-derived soils or on igneous-derived soils that are damp during growing season
Elevation 1000–2000 m (3300–6600 ft) 1400–2100 m (4600–6900 ft)
Distribution
from FNA
CO; KS; ND; NE; NM; OK; SD; TX; WY
[WildflowerSearch map]
from FNA
TX; Mexico (Chihuahua, Coahuila)
[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.)

In the flora area, Packera millelobata occurs only in the trans-Pecos region of western Texas. It has been confused with P. tampicana. Their ranges overlap along the Rio Grande; P. millelobata has leaves with narrow terminal lobes; P. tampicana has terminal lobes as wide as the leaf blade. In addition, P. tampicana is annual with pronounced taproots; P. millelobata is perennial with taprooted caudices.

(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. 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 millelobatus
Name authority (Rydberg) W. A. Weber & Á. Löve: Phytologia 49: 48. (1981) (Rydberg) W. A. Weber & Á. Löve: Phytologia 49: 47. (1981)
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