Packera glabella |
Packera paupercula |
|
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butterweed |
balsam groundsel, Canadian butterweed |
|
Habit | Annuals or biennials, 20–70+ cm; fibrous-rooted (caudices relatively short, weak). | Perennials, 20–45+ cm; subrhizomatous (bases weakly branched, ascending to erect). |
Stems | 1 (striated, frequently hollow, often pink- to purple-tinged), glabrous or leaf axils sparsely tomentose. |
1 or 2–4, loosely clustered, glabrous or sparsely tomentose proximally. |
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. |
petiolate; blades lanceolate to narrowly elliptic or oblanceolate, 30–60+ × 10–20+ mm, bases tapering, sometimes obtuse, margins subentire to dentate or serrate. |
Cauline leaves | gradually reduced (weakly clasping, similar to basal). |
gradually reduced (proximals petiolate, sublyrate; mids sessile, not clasping, lanceolate, dissected, incised, or lacerate; distals sessile, bractlike). |
Peduncles | bracteate, glabrous or bases tomentose. |
usually bracteate, sometimes ebracteate, glabrous. |
Ray florets | (8–)13; corolla laminae 7–9 mm. |
0, 8, or 13; corolla laminae (pale yellow) 5–10+ mm. |
Disc florets | 35–50+; corolla tubes 2.5–3.5 mm, limbs 2–3 mm. |
50–65+; corolla tubes 2–3 mm, limbs 2–3 mm. |
Phyllaries | (13–)21, green, 5–7 mm, glabrous. |
13 or 21, green, 5–8+ mm, glabrous. |
Calyculi | conspicuous (bractlets 2.5–4 mm). |
inconspicuous. |
Heads | 8–30+ in umbelliform or cymiform arrays (robust plants with multiple arrays). |
2–10+ in loose or compact, corymbiform arrays. |
Cypselae | 1–1.5 mm, sparsely hirtellous on ribs or glabrous; pappi 3–4 mm. |
1–2 mm, usually glabrous, sometimes hispidulous on ribs; pappi 3.5–4.5 mm. |
2n | = 46. |
= 44, 46, 92. |
Packera glabella |
Packera paupercula |
|
Phenology | Flowering (Feb–)mid Mar–late May. | Flowering May–late Jun (south), late Jun–early Aug (north). |
Habitat | Open wet areas, edges of woodlands, stream banks, roadsides, meadows, marshes, fallow fields | Wet meadows, open woodlands, along streams, rocky outcrops |
Elevation | 0–600 m (0–2000 ft) | 0–3000 m (0–9800 ft) |
Distribution |
AL; AR; FL; GA; IL; IN; KS; KY; LA; MO; MS; NC; NE; OH; OK; SC; TN; TX
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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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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.) |
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.) |
Source | FNA vol. 20, p. 588. | FNA vol. 20, p. 595. |
Parent taxa | Asteraceae > tribe Senecioneae > Packera | Asteraceae > tribe Senecioneae > Packera |
Sibling taxa | ||
Synonyms | Senecio glabellus, Senecio carolinianus, Senecio densiflorus, Senecio lobatus, Senecio lyratus, Senecio mississipianus | 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 |
Name authority | (Poiret) C. Jeffrey: Kew Bull. 47: 101. (1992) | (Michaux) Á. Löve & D. Löve: Bot. Not. 128: 520. (1976) |
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