Flora of North America species comparison

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Packera glabella

Packera castoreus

butterweed

beaver mountain ragwort
Habit Annuals or biennials, 20–70+ cm; fibrous-rooted (caudices relatively short, weak). Perennials, 3–9+ cm; usually fibrous-rooted, sometimes rhizomatous (bases erect or ascending, branched).
Stems

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

1 or 2–3, (white) woolly-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 obovate to oblanceolate or spatulate, 10–20+ × 5–18 mm, bases tapering, margins entire or crenate (abaxial faces densely tomentose, adaxial glabrescent).
Cauline leaves

gradually reduced (weakly clasping, similar to basal).

gradually reduced (becoming sessile and bractlike).
Peduncles

bracteate, glabrous or bases tomentose.

ebracteate.
Ray florets

(8–)13;

corolla laminae 7–9 mm.

0.
Disc florets

35–50+;

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

not seen.
Phyllaries

(13–)21, green, 5–7 mm, glabrous.

purple-tinged, 7–10 mm, tomentose (ciliate distally, apices with dense tufts of hairs).
Calyculi

conspicuous (bractlets 2.5–4 mm).

inconspicuous.
Heads

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

1–4+, in corymbiform arrays.
Cypselae

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

pappi 3–4 mm.

not seen (reported to be glabrous).
2n

= 46.

Packera glabella

Packera castoreus
Phenology Flowering (Feb–)mid Mar–late May. Flowering late Jul–late Sep.
Habitat Open wet areas, edges of woodlands, stream banks, roadsides, meadows, marshes, fallow fields Ridges, spruce-fir communities, igneous soils
Elevation 0–600 m (0–2000 ft) 3300–3900 m (10800–12800 ft)
Distribution
from FNA
AL; AR; FL; GA; IL; IN; KS; KY; LA; MO; MS; NC; NE; OH; OK; SC; TN; TX
[WildflowerSearch map]
[BONAP county map]
from FNA
UT
[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.)

Of conservation concern.

Packera castoreus is known only from relatively few collections from the Tushar Mountains in Beaver and Piute counties. Welsh speculated that it may have some affinities with P. cana and P. werneriifolia.

(Discussion copyrighted by Flora of North America; reprinted with permission.)
Source FNA vol. 20, p. 588. FNA vol. 20, p. 582.
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. 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 glabellus, Senecio carolinianus, Senecio densiflorus, Senecio lobatus, Senecio lyratus, Senecio mississipianus Senecio castoreus
Name authority (Poiret) C. Jeffrey: Kew Bull. 47: 101. (1992) (S. L. Welsh) Kartesz: in J. T. Kartesz and C. A. Meacham, Synth. N. Amer. Fl., nomencl. innov. 20. (1999)
Web links 
Unless otherwise noted, all data comes from the online version of the Flora of North America, who have made most of their content available via a Creative Commons license (CC BY 4.0).



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