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butterweed

Great Plains ragwort

Habit Annuals or biennials, 20–70+ cm; fibrous-rooted (caudices relatively short, weak). Annuals, 20–50+ cm; taprooted (caudices ascending to erect).
Stems

1 (striated, frequently hollow, often pink- to purple-tinged), glabrous or leaf axils sparsely tomentose.

1 or 2–6+, clustered (bases cyanic), glabrous or leaf axils sparsely tomentose.

Basal leaves

(and proximal cauline) obscurely petiolate;

blades obovate to oblanceolate, sometimes lyrate (lateral lobes to 5 pairs, terminal lobes larger than laterals), 50–150+ × 10–30+ mm, bases tapering, ultimate margins crenate to irregularly undulate.

(and proximal cauline) petiolate;

blades oblanceolate to spatulate (usually pinnately lobed, lateral lobes 1–6+ pairs, their bases petioluliform, terminal lobes usually larger than laterals, often reniform to ± orbiculate, midribs sometimes ± winged and/or toothed between the primary lobes), 40–120+ × 10–30+ mm, bases ± cuneate, ultimate margins subentire or irregularly crenate, dentate, or lobed.

Cauline leaves

gradually reduced (weakly clasping, similar to basal).

gradually reduced (± petiolate or sessile, clasping; often auriculate, pinnately dissected to pinnately lobed).

Peduncles

bracteate, glabrous or bases tomentose.

bracteate, glabrous.

Ray florets

(8–)13;

corolla laminae 7–9 mm.

8 or 13;

corolla laminae 3–7 mm.

Disc florets

35–50+;

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

30–45(–100+);

corolla tubes 1.5–2.5 mm, limbs (1.5–)2.5–3.5 mm.

Phyllaries

(13–)21, green, 5–7 mm, glabrous.

13 or 21, green (tips sometimes reddish), 3–7 mm, glabrous.

Calyculi

conspicuous (bractlets 2.5–4 mm).

inconspicuous or 0.

Heads

8–30+ in umbelliform or cymiform arrays (robust plants with multiple arrays).

4–25+ in corymbiform arrays.

Cypselae

1–1.5 mm, sparsely hirtellous on ribs or glabrous;

pappi 3–4 mm.

1–1.5 mm, hirtellous on ribs;

pappi 3–5 mm.

2n

= 46.

= 46.

Packera glabella

Packera tampicana

Phenology Flowering (Feb–)mid Mar–late May. Flowering Feb–Jun.
Habitat Open wet areas, edges of woodlands, stream banks, roadsides, meadows, marshes, fallow fields Disturbed, wet, sandy or clay sites, roadsides, stream banks, waste areas
Elevation 0–600 m (0–2000 ft) 0–1000 m (0–3300 ft)
Distribution
from FNA
AL; AR; FL; GA; IL; IN; KS; KY; LA; MO; MS; NC; NE; OH; OK; SC; TN; TX
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[BONAP county map]
from FNA
AR; KS; LA; OK; TX; Mexico
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[BONAP county map]
Discussion

Packera glabella is common and almost weedy in wet, partially shaded places. The hollow, striated stems of P. glabella are distinctive.

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

Packera tampicana is fairly widespread along the Gulf Coastal Plain and north and in Mexico. Morphologically, P. tampicana most closely resembles P. glabella; the former grows in very wet, sandy or clay soils and open sunlight, the latter grows in drier habitats, usually in partial shade.

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

Source FNA vol. 20, p. 588. FNA vol. 20, p. 600.
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. 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
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. texensis, P. tomentosa, P. tridenticulata, P. werneriifolia
Synonyms Senecio glabellus, Senecio carolinianus, Senecio densiflorus, Senecio lobatus, Senecio lyratus, Senecio mississipianus Senecio tampicanus, Senecio greggii, Senecio imparipinnatus
Name authority (Poiret) C. Jeffrey: Kew Bull. 47: 101. (1992) (de Candolle) C. Jeffrey: Kew Bull. 47: 101. (1992)
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