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threetooth ragwort

golden groundsel, golden ragwort

Habit Perennials, 10–30+ cm; taprooted (caudices ascending to erect). Perennials, 30–60+ cm; rhizomatous and/or fibrous-rooted (rhizomes or caudices erect to horizontal).
Stems

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

1 or 2–3+, clustered, glabrous or 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 cordate to reniform, 20–60 × 20–60 mm, bases abruptly contracted or ± cordate, margins crenate to crenate-serrate (apices rounded, faces glabrous).

Cauline leaves

gradually reduced (± petiolate or sessile).

gradually reduced (petiolate or sessile, not clasping; blades oblong to lyrate, lateral lobes 2–4 pairs).

Peduncles

bracteate, glabrous or sparsely tomentose.

bracteate, glabrous or sparsely tomentose.

Ray florets

8–10(–13);

corolla laminae 5–8+ mm.

(8–)10–13;

corolla laminae 8–10+ mm.

Disc florets

45–60+;

corolla tubes 3–3.5 mm, limbs 4–5 mm.

55–70+;

corolla tubes 3–3.5 mm, limbs 2–2.5 mm.

Phyllaries

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

13–21, green (tips purple or black), 6–8 mm, glabrous or sparsely tomentose proximally.

Calyculi

inconspicuous.

inconspicuous.

Heads

4–15+ in corymbiform arrays.

6–20+ in corymbiform to subumbelliform arrays.

Cypselae

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

pappi 5–6 mm.

1–1.5 mm, glabrous;

pappi 4.5–5.5 mm.

2n

= 46.

= 44.

Packera tridenticulata

Packera aurea

Phenology Flowering late May–early Jul. Flowering late Feb–early May (south), late May–early Aug (north).
Habitat Open, dry areas, roadsides, gravelly or sandy slopes, short-grass prairies or sagebrush scrubs Damp and swampy places in woodlands, meadows, along gravel banks and streambeds, acidic or sandy/gravelly soils
Elevation 1000–2000 m (3300–6600 ft) 0–1500 m (0–4900 ft)
Distribution
from FNA
CO; KS; ND; NE; NM; OK; SD; TX; WY
[WildflowerSearch map]
from FNA
AL; AR; CT; DC; FL; GA; IA; IL; IN; KY; MA; MD; ME; MI; MN; MO; MS; NC; ND; NH; NJ; NY; OH; OK; PA; RI; SC; SD; TN; VA; VT; WI; WV; MB; NB; NL; NS; ON; PE; QC; SPM
[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 aurea is abundant and widespread throughout eastern United States and Canada. It reproduces asexually from branched rhizomes or from adventitious shoots. Putative hybrids between P. aurea and P. paupercula, P. pseudaurea, P. schweinitziana, and P. tomentosa have been reported.

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

Source FNA vol. 20, p. 601. FNA vol. 20, p. 579.
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. 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. tridenticulata, P. werneriifolia
Synonyms Senecio tridenticulatus, Senecio acutidens, Senecio compactus, Senecio densus, Senecio oblanceolatus Senecio aureus, Senecio aureus var. aquilonius, Senecio aureus var. ashei, Senecio aureus var. aurantiacus, Senecio aureus var. gracilis, Senecio aureus var. intercursus, Senecio gracilis
Name authority (Rydberg) W. A. Weber & Á. Löve: Phytologia 49: 48. (1981) (Linnaeus) Á. Löve & D. Löve: Bot. Not. 128: 520. (1976)
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