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threetooth ragwort

Oak Creek ragwort

Habit Perennials, 10–30+ cm; taprooted (caudices ascending to erect). Perennials, 60–100+ cm; taprooted (caudices subligneous, ascending to erect).
Stems

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

1 or 2–4, clustered (proximally deeply purple-tinged, distally lightly tinged), glabrous or tomentose at bases and in leaf axils.

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 obovate or lyrate (pinnately lobed, lateral lobes 2–6+ pairs, their bases petioluliform, terminal lobes larger than laterals, midribs narrowly winged), 60–160+ × 20–40+ mm, bases wide, ultimate margins sharply dentate, crenate-dentate, or irregularly incised.

Cauline leaves

gradually reduced (± petiolate or sessile).

gradually reduced (petiolate or sessile; shallowly lobed, midribs ± winged, distals bractlike, dentate to incised).

Peduncles

bracteate, glabrous or sparsely tomentose.

ebracteate, glabrous.

Ray florets

8–10(–13);

corolla laminae 5–8+ mm.

(8–)13;

corolla laminae 6–10+ mm.

Disc florets

45–60+;

corolla tubes 3–3.5 mm, limbs 4–5 mm.

60–70+;

corolla tubes 2–3 mm, limbs 3.5–4.5 mm.

Phyllaries

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

(13–)21, green (tips yellow), 5–7 mm, glabrous (tips sometimes hairy).

Calyculi

inconspicuous.

inconspicuous.

Heads

4–15+ in corymbiform arrays.

15–40+ in open, cymiform arrays.

Cypselae

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

pappi 5–6 mm.

1.5–2 mm, glabrous or ± scabrellous;

pappi 5.5–6.5 mm.

2n

= 46.

= 92.

Packera tridenticulata

Packera quercetorum

Phenology Flowering late May–early Jul. Flowering mid Apr–early Jun.
Habitat Open, dry areas, roadsides, gravelly or sandy slopes, short-grass prairies or sagebrush scrubs Rocky soils, open areas, scrub-oak and pinyon-pine forests, chaparral
Elevation 1000–2000 m (3300–6600 ft) 800–2200 m (2600–7200 ft)
Distribution
from FNA
CO; KS; ND; NE; NM; OK; SD; TX; WY
[WildflowerSearch map]
from FNA
AZ; NM
[WildflowerSearch map]
[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.)

Packera quercetorum is found only infrequently and in relatively small populations in central and southern Arizona and west-central New Mexico. The plants are robust and have probable affinities to P. multilobata. The plants have a bluish tinge when freshly collected and are distinctive in the field.

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

Source FNA vol. 20, p. 601. FNA vol. 20, p. 598.
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. musiniensis, P. neomexicana, P. obovata, P. ogotorukensis, P. pauciflora, P. paupercula, P. plattensis, P. porteri, P. pseudaurea, 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 quercetorum, Senecio macropus
Name authority (Rydberg) W. A. Weber & Á. Löve: Phytologia 49: 48. (1981) (Greene) C. Jeffrey: Kew Bull. 47: 101. (1992)
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