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balsam groundsel, Canadian butterweed

cut-leaf butterweed, wide-head groundsel

Habit Perennials, 20–45+ cm; subrhizomatous (bases weakly branched, ascending to erect). Perennials, 20–50+ cm, taprooted (caudices branched, ascending to erect, woody).
Stems

1 or 2–4, loosely clustered, glabrous or sparsely tomentose proximally.

1 or, usually, multiple, clustered, densely tomentose to glabrescent.

Basal leaves

petiolate;

blades lanceolate to narrowly elliptic or oblanceolate, 30–60+ × 10–20+ mm, bases tapering, sometimes obtuse, margins subentire to dentate or serrate.

(soon withering), petiolate;

blades lyrate (lateral lobes 2–6+ pairs), ovate, obovate, or spatulate, 70–100+ × 20–30+ mm, bases tapering, ultimate margins irregularly and coarsely serrate-dentate.

Cauline leaves

gradually reduced (proximals petiolate, sublyrate; mids sessile, not clasping, lanceolate, dissected, incised, or lacerate; distals sessile, bractlike).

gradually reduced (± petiolate, proximal and mid similar to basal, terminal lobes smaller than laterals; distal sessile, incised).

Peduncles

usually bracteate, sometimes ebracteate, glabrous.

bracteate, sparsely to densely lanate-tomentose.

Ray florets

0, 8, or 13;

corolla laminae (pale yellow) 5–10+ mm.

8 or 13;

corolla laminae 10–15 mm.

Disc florets

50–65+;

corolla tubes 2–3 mm, limbs 2–3 mm.

35–50+;

corolla tubes 3.5–4.5 mm, limbs 2.5–3.5 mm.

Phyllaries

13 or 21, green, 5–8+ mm, glabrous.

13 or 21, green (tips sometimes yellow), 8–10+ mm, densely tomentose proximally, glabrescent distally.

Calyculi

inconspicuous.

inconspicuous (bractlets tomentose).

Heads

2–10+ in loose or compact, corymbiform arrays.

5–20+ in open or compact (rarely), cymiform arrays.

Cypselae

1–2 mm, usually glabrous, sometimes hispidulous on ribs;

pappi 3.5–4.5 mm.

1–1.5 mm, glabrous;

pappi 6–7 mm.

2n

= 44, 46, 92.

= 46.

Packera paupercula

Packera eurycephala

Phenology Flowering May–late Jun (south), late Jun–early Aug (north).
Habitat Wet meadows, open woodlands, along streams, rocky outcrops
Elevation 0–3000 m (0–9800 ft)
Distribution
from FNA
AK; AL; CO; DC; GA; IA; ID; IL; IN; KY; MA; MD; ME; MI; MN; MT; NC; ND; NH; NJ; NY; OH; PA; SD; TN; UT; VT; WA; WI; WV; WY; AB; BC; MB; NB; NL; NS; NT; NU; ON; PE; QC; SK; YT
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from FNA
CA; OR
[WildflowerSearch map]
[BONAP county map]
Discussion

Ecologically and morphologically, Packera paupercula is the most variable species of the genus in North America. Some “phases” have been treated as separate species, subspecies, varieties, forms, and races. Variation within P. paupercula hints at some interesting evolutionary relationships; characteristics used to separate taxa overlap. Much of the morphologic variation in this species may be due to hybridization and introgression. I do not recognize any of the infraspecific taxa that have been proposed.

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

Varieties 2 (2 in the flora).

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

Key
1. Stems (1–)2–6; leaf blades: margins usually serrate-dentate, sometimes deeply dissected, midribs winged
var. eurycephala
1. Stems 1; leaf blades finely dissected, lateral lobes also dissected, midribs not or weakly winged
var. lewisrosei
Source FNA vol. 20, p. 595. FNA vol. 20, p. 586.
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. 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. 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
Subordinate taxa
P. eurycephala var. eurycephala, P. eurycephala var. lewisrosei
Synonyms Senecio pauperculus, Senecio balsamitae, Senecio balsamitae var. firmifolius, Senecio balsamitae var. thomsoniensis, Senecio crawfordii, Senecio flavovirens, Senecio gaspensis, Senecio multnomensis, Senecio robbinsii var. subtomentosus, Senecio tweedyi Senecio eurycephalus
Name authority (Michaux) Á. Löve & D. Löve: Bot. Not. 128: 520. (1976) (Torrey & A. Gray) W. A. Weber & Á. Löve: Phytologia 49: 46. (1981)
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