Packera glabella

(Poiret) C. Jeffrey

Kew Bull. 47: 101. 1992.

Common names: Butterweed
Basionym: Senecio glabellus Poiret in J. Lamarck et al., Encycl. 7: 102. 1806 Senecio lyratus Michaux 1803
Synonyms: Senecio carolinianus Sprengel Senecio densiflorus M. Martens Senecio lobatus Persoon Senecio mississipianus de Candolle
Treatment appears in FNA Volume 20. Treatment on page 588. Mentioned on page 548, 575, 601.

Annuals or biennials, 20–70+ cm; fibrous-rooted (caudices relatively short, weak). Stems 1 (striated, frequently hollow, often pink- to purple-tinged), 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. Cauline leaves gradually reduced (weakly clasping, similar to basal). Heads 8–30+ in umbelliform or cymiform arrays (robust plants with multiple arrays). Peduncles bracteate, glabrous or bases tomentose. Calyculi conspicuous (bractlets 2.5–4 mm). Phyllaries (13–)21, green, 5–7 mm, glabrous. Ray florets (8–)13; corolla laminae 7–9 mm. Disc florets 35–50+; corolla tubes 2.5–3.5 mm, limbs 2–3 mm. Cypselae 1–1.5 mm, sparsely hirtellous on ribs or glabrous; pappi 3–4 mm. 2n = 46.

Phenology: Flowering (Feb–)mid Mar–late May.
Habitat: Open wet areas, edges of woodlands, stream banks, roadsides, meadows, marshes, fallow fields
Elevation: 0–600 m



Ala., Ark., Fla., Ga., Ill., Ind., Kans., Ky., La., Miss., Mo., Nebr., N.C., Ohio, Okla., S.C., Tenn., Tex.


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

Selected References


Lower Taxa

... more about "Packera glabella"
Debra K. Trock +
(Poiret) C. Jeffrey +
Senecio glabellus +  and Senecio lyratus +
Butterweed +
Ala. +, Ark. +, Fla. +, Ga. +, Ill. +, Ind. +, Kans. +, Ky. +, La. +, Miss. +, Mo. +, Nebr. +, N.C. +, Ohio +, Okla. +, S.C. +, Tenn. +  and Tex. +
0–600 m +
Open wet areas, edges of woodlands, stream banks, roadsides, meadows, marshes, fallow fields +
Flowering (Feb–)mid Mar–late May. +
Illustrated +  and Endemic +
Senecio carolinianus +, Senecio densiflorus +, Senecio lobatus +  and Senecio mississipianus +
Packera glabella +
species +