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serpentine groundsel, Siskiyou butterweed, western ragwort

Habit Perennials, 7–15+ cm; fibrous-rooted (caudices relatively slender). Perennials, 5–10 cm; ± rhizomatous (bases loosely branched, elongated, horizontal to ascending).
Stems

1, glabrous or sparsely tomentose.

1 (sometimes branched from bases), densely white- or gray-tomentose.

Basal leaves

(and proximal cauline) petiolate;

blades ovate, oblanceolate, or spatulate, 10–30 × 5–20 mm, bases tapering, sometimes obtuse, margins entire, subentire, or dentate.

petiolate;

blades oblanceolate, 20–30+ × 5–13+ mm, bases tapering, margins pinnatifid to crenate.

Cauline leaves

abruptly reduced (sessile, clasping; bractlike, entire).

gradually reduced (sessile; proximal and mid nearly equaling basals, distals bractlike).

Peduncles

bracteate (bractlets red-tinged), densely lanate-tomentose.

ebracteate, tomentose.

Ray florets

(8–)13;

corolla laminae 6–10+ mm.

0 or 1;

corolla laminae ca. 6 mm.

Disc florets

35–50+;

corolla tubes 2.5–3.5 mm, limbs 3–4 mm.

not seen.

Phyllaries

(13–)21, green (tips red or dark red), densely tomentose proximally.

8–13, yellow-green to purple (or with purplish midstripes), 8–9.5 mm, sparsely tomentose (apices rounded).

Calyculi

conspicuous (bractlets narrow, red-tinged).

0 or inconspicuous.

Heads

1–4+ in corymbiform arrays.

3–15+ in corymbiform arrays.

Cypselae

1.5–2 mm, glabrous;

pappi 5–6 mm.

not seen (reported to be glabrous).

2n

= 46.

= 46.

Packera hesperia

Packera musiniensis

Phenology Flowering mid Apr–mid Jun. Flowering mid Jul–mid Aug.
Habitat Serpentine derived soils, open woodland scrub Subalpine and alpine ridges, talus or scree slopes, barren areas on Flagstaff limestone
Elevation 500–2500 m (1600–8200 ft) 2900–3300 m (9500–10800 ft)
Distribution
from FNA
CA; OR
[WildflowerSearch map]
[BONAP county map]
from FNA
UT
[BONAP county map]
Discussion

Of conservation concern.

Packera hesperia is known only from the Siskiyou Mountains.

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

Of conservation concern.

Packera musiniensis is a high-elevation dwarf species; its affinities within Packera are still uncertain. Welsh believed it to be allied to P. cana or P. multilobata, or both.

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

Source FNA vol. 20, p. 589. FNA vol. 20, p. 592.
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. 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. 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. 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. tomentosa, P. tridenticulata, P. werneriifolia
Synonyms Senecio hesperius, Senecio auleticus Senecio musiniensis
Name authority (Greene) W. A. Weber & Á. Löve: Phytologia 49: 47. (1981) (S. L. Welsh) Trock: Sida 21: 1643. (2005)
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