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plains butterweed, prairie groundsel

woolly ragwort

Habit Biennials or perennials, 20–60+ cm; rhizomatous and/or fibrous-rooted (bases erect to suberect), sometimes stoloniferous (mostly eastern populations). Perennials, 30–60+ cm; taprooted (caudices relatively thick, weakly ascending or erect), sometimes stoloniferous.
Stems

1 or 2–3, clustered, floccose-tomentose proximally and in leaf axils, otherwise sparsely tomentose or glabrescent.

1, densely lanate-tomentose proximally, floccose-tomentose to glabrescent distally.

Basal leaves

(and proximal cauline) petiolate;

blades narrowly elliptic to elliptic-ovate or oblanceolate to suborbiculate or sublyrate, 20–70+ × 10–30+ mm, bases tapering to rounded or abruptly contracted, margins subentire to crenate, serrate-dentate, or pinnately lobed (abaxial faces floccose-tomentose, especially along midribs, ± glabrescent).

(and proximal cauline) petiolate;

blades lanceolate to narrowly ovate or elliptic, 40–120+ × 20–50+ mm, bases tapering, sometimes oblique, margins subentire, crenate, or serrate-dentate.

Cauline leaves

gradually reduced (petiolate, sublyrate or pinnatisect, abaxial faces sparsely hairy; distals sessile, subentire to irregularly dissected).

gradually reduced (± petiolate or sessile, weakly clasping; dentate to pinnately lobed).

Peduncles

conspicuously bracteate, sparsely to densely tomentose.

bracteate, sparsely to densely tomentose.

Ray florets

8–10;

corolla laminae 9–10 mm.

10 or 13;

corolla laminae 6–8+ mm.

Disc florets

60–70+;

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

50–60+;

corolla tubes 3.5–4 mm, limbs 3–3.5 mm.

Phyllaries

13 or 21, green (tips sometimes cyanic), 5–6+ mm, densely tomentose proximally, glabrescent distally.

13 or 21, light green, 5–8 mm, usually glabrous (sometimes hairy proximally).

Calyculi

inconspicuous.

inconspicuous.

Heads

6–20+ in open or congested, corymbiform arrays.

10–30+ in open, corymbiform arrays (more in robust individuals).

Cypselae

1.5–2.5 mm, usually hirtellous, sometimes glabrous;

pappi 6.5–7.5 mm.

1–1.5 mm, hispid;

pappi 5–7 mm.

2n

= 46, 92.

= 46.

Packera plattensis

Packera tomentosa

Phenology Flowering mid Apr–early Jun(–mid Jul, north). Flowering (Mar–)May–early Jun.
Habitat Prairies, meadows, open wooded areas, along highways, railroads, around mining and construction areas, usually on limestone Open meadows, roadways, sandy or shallow soils overlying granitic outcrops
Elevation 50–1800 m (200–5900 ft) 0–500 m (0–1600 ft)
Distribution
from FNA
AR; CO; GA; IA; IL; IN; KS; LA; MI; MN; MO; MS; MT; ND; NE; NM; OH; OK; PA; SD; TN; VA; WI; WY; ON; SK
[WildflowerSearch map]
[BONAP county map]
from FNA
AL; AR; DE; FL; GA; LA; MD; NC; NJ; OK; SC; TX; VA
[WildflowerSearch map]
[BONAP county map]
Discussion

Packera plattensis is abundant, widespread, and almost weedy. Putative hybrids with other species are known. Plants in mesic, remnant prairies in the east are sometimes stoloniferous.

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

Packera tomentosa is common throughout most of its range. The basal and proximal cauline leaves are held at about 45 degrees to the stems.

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

Source FNA vol. 20, p. 596. FNA vol. 20, p. 601.
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. paupercula, 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. tampicana, P. texensis, P. tridenticulata, P. werneriifolia
Synonyms Senecio plattensis, Senecio pseudotomentosus Senecio tomentosus, Cineraria integrifolia var. minor, S. alabamensis
Name authority (Nuttall) W. A. Weber & Á. Löve: Phytologia 49: 48. (1981) (Michaux) C. Jeffrey: Kew Bull. 47: 101. (1992)
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