Packera plattensis |
Packera millelobata |
|
---|---|---|
plains butterweed, prairie groundsel |
Uinta ragwort |
|
Habit | Biennials or perennials, 20–60+ cm; rhizomatous and/or fibrous-rooted (bases erect to suberect), sometimes stoloniferous (mostly eastern populations). | Perennials, 30–50+ cm; taprooted or ± rhizomatous (bases weakly creeping, horizontal to erect). |
Stems | 1 or 2–3, clustered, floccose-tomentose proximally and in leaf axils, otherwise sparsely tomentose or glabrescent. |
1 or 2–5+, loosely clustered, glabrous or leaf axils sparsely tomentose. |
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 narrowly lanceolate (pinnatifid, lateral lobes 6+ pairs, their bases petioluliform, terminal lobes smaller than laterals), 60–100 × 10–20 mm, bases tapering, ultimate margins dentate. |
Cauline leaves | gradually reduced (petiolate, sublyrate or pinnatisect, abaxial faces sparsely hairy; distals sessile, subentire to irregularly dissected). |
gradually reduced (sessile). |
Peduncles | conspicuously bracteate, sparsely to densely tomentose. |
bracteate or ebracteate, glabrous. |
Ray florets | 8–10; corolla laminae 9–10 mm. |
(8–)13; corolla laminae 8–10+ mm. |
Disc florets | 60–70+; corolla tubes 2.5–3.5 mm, limbs 3.5–4.5 mm. |
40–55+; corolla tubes 2–3 mm, limbs 2–3 mm. |
Phyllaries | 13 or 21, green (tips sometimes cyanic), 5–6+ mm, densely tomentose proximally, glabrescent distally. |
(13–)21, green (tips yellow), 4–6+ mm, glabrous. |
Calyculi | inconspicuous. |
inconspicuous. |
Heads | 6–20+ in open or congested, corymbiform arrays. |
6–20+ in corymbiform arrays. |
Cypselae | 1.5–2.5 mm, usually hirtellous, sometimes glabrous; pappi 6.5–7.5 mm. |
1–1.5 mm, hirtellous on ribs; pappi 3.5–4.5 mm. |
2n | = 46, 92. |
|
Packera plattensis |
Packera millelobata |
|
Phenology | Flowering mid Apr–early Jun(–mid Jul, north). | Flowering late Mar–early Jun. |
Habitat | Prairies, meadows, open wooded areas, along highways, railroads, around mining and construction areas, usually on limestone | Streambeds, openings in wooded areas on limestone-derived soils or on igneous-derived soils that are damp during growing season |
Elevation | 50–1800 m (200–5900 ft) | 1400–2100 m (4600–6900 ft) |
Distribution |
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
|
TX; Mexico (Chihuahua, Coahuila) |
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.) |
In the flora area, Packera millelobata occurs only in the trans-Pecos region of western Texas. It has been confused with P. tampicana. Their ranges overlap along the Rio Grande; P. millelobata has leaves with narrow terminal lobes; P. tampicana has terminal lobes as wide as the leaf blade. In addition, P. tampicana is annual with pronounced taproots; P. millelobata is perennial with taprooted caudices. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 20, p. 596. | FNA vol. 20, p. 592. |
Parent taxa | Asteraceae > tribe Senecioneae > Packera | Asteraceae > tribe Senecioneae > Packera |
Sibling taxa | ||
Synonyms | Senecio plattensis, Senecio pseudotomentosus | Senecio millelobatus |
Name authority | (Nuttall) W. A. Weber & Á. Löve: Phytologia 49: 48. (1981) | (Rydberg) W. A. Weber & Á. Löve: Phytologia 49: 47. (1981) |
Web links |