Packera plattensis |
Packera layneae |
|
---|---|---|
plains butterweed, prairie groundsel |
Layne's ragwort |
|
Habit | Biennials or perennials, 20–60+ cm; rhizomatous and/or fibrous-rooted (bases erect to suberect), sometimes stoloniferous (mostly eastern populations). | Perennials, 40–70+ cm; taprooted (caudices erect to suberect, branched, stout). |
Stems | 1 or 2–3, clustered, floccose-tomentose proximally and in leaf axils, otherwise sparsely tomentose or glabrescent. |
1 or 3–4+, clustered, sparsely tomentose to glabrescent. |
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, relatively thick and turgid) petiolate; blades narrowly elliptic or lanceolate to oblanceolate, 40–70+ × 5–20+ mm, bases tapering, margins entire or subentire to weakly and irregularly dentate (especially at apices). |
Cauline leaves | gradually reduced (petiolate, sublyrate or pinnatisect, abaxial faces sparsely hairy; distals sessile, subentire to irregularly dissected). |
gradually reduced (distal sessile, bractlike). |
Peduncles | conspicuously bracteate, sparsely to densely tomentose. |
bracteate (bractlets usually red-tipped), sparsely tomentose to glabrate. |
Ray florets | 8–10; corolla laminae 9–10 mm. |
5 or 8; corolla laminae 12–16 mm. |
Disc florets | 60–70+; corolla tubes 2.5–3.5 mm, limbs 3.5–4.5 mm. |
50–60+; corolla tubes 3.5–4.5 mm, limbs 4.5–5.5 mm. |
Phyllaries | 13 or 21, green (tips sometimes cyanic), 5–6+ mm, densely tomentose proximally, glabrescent distally. |
13 or 21, dark green proximally, becoming light green distally (tips red), 7–11+ mm, floccose-tomentose proximally. |
Calyculi | inconspicuous. |
conspicuous (bractlets red-tipped). |
Heads | 6–20+ in open or congested, corymbiform arrays. |
5–12+ in open, cymiform arrays. |
Cypselae | 1.5–2.5 mm, usually hirtellous, sometimes glabrous; pappi 6.5–7.5 mm. |
2.5–3.5 mm, glabrous; pappi 7–8 mm. |
2n | = 46, 92. |
= 92. |
Packera plattensis |
Packera layneae |
|
Phenology | Flowering mid Apr–early Jun(–mid Jul, north). | Flowering early May–early Jul. |
Habitat | Prairies, meadows, open wooded areas, along highways, railroads, around mining and construction areas, usually on limestone | Openings, disturbed areas, in chaparral, serpentine soils |
Elevation | 50–1800 m (200–5900 ft) | 300–900 m (1000–3000 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
|
CA |
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.) |
Of conservation concern. Packera layneae is known only from the foothills of the western slope of the Sierra Nevada. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 20, p. 596. | FNA vol. 20, p. 590. |
Parent taxa | Asteraceae > tribe Senecioneae > Packera | Asteraceae > tribe Senecioneae > Packera |
Sibling taxa | ||
Synonyms | Senecio plattensis, Senecio pseudotomentosus | Senecio layneae, Senecio fastigiatus var. layneae |
Name authority | (Nuttall) W. A. Weber & Á. Löve: Phytologia 49: 48. (1981) | (Greene) W. A. Weber & Á. Löve: Phytologia 49: 47. (1981) |
Web links |