Packera macounii

From Puget Prairie Plants
  • Scientific Name: Packera macounii
  • Family: Asteraceae
  • Common name: Puget butterweed, long rayed groundsel, Macoun's groundsel, Siskiyou Mountain ragwort
  • Synonyms/Misapplications: Senecio macounii, Senecio ligulifolius
  • Codon: PACMAC

Photo by Rod Gilbert, 2008, also featured on Main Page


Scientific classification
Kingdom: Plantae
Subkingdom: Viridiplantae
Phylum: Tracheophyta
Subphylum: Spermatophytina
Class: Magnoliopsida
Subclass: Asteranae
Order: Asterales
Family: Asteraceae
Genus: Packera Á. Löve & D. Löve
Species: Packera macounii (Greene) W.A. Weber & Á. Löve
  • Senecio macounii Greene
  • Senecio ligulifolius Greene



Perennial herb, rising from fibrous roots or horizontal rhizomes, variable hairiness from nearly glabrous to wooly-hairy.

Basal leaves thick, lanceolate stalked, 4-27 cm long including the stalk, sparcely white-woolly when young becoming hairless by flowering time, variable margins- from entire to coarsely toothed. Cauline leaves similar, from lanceolate to linear, reduced upwards, becoming sessile up the stalk. Tomentum more dense on lower leaf surfaces.

Capitate inflorescences in flat-topped arrays. Involucral bracts lanceolate, with translucent margins, hairy at the tips. Ray and disk flowers yellow.

Fruit is an achene. [2][3]


West Cascades, Victoria Island through Puget Trough and Willamette Valley to Southern Oregon.[3]

This plant is listed with the State of Washington as critically imperiled due to the reduction in native prairie acreage. Though it was once found in a wider range, the only known remaining population in south Puget lowland prairies is on Joint Base Lewis-McChord.[4]


Dry open forests, disturbed areas and rock outcrops or limestone quarries in the lowland zone[2]


Provides nectar for pollinators.


"Packera macounii grows in a manner common to many perennials from the aster plant family on the West Coast of the United States. Many bloom in late spring to early summer and ripen seed in the hottest, driest part of the year. Summer rain is uncommon in most lowland areas of western North America, and plants must develop adaptations to set seed under dry conditions. The leaves can persist and provide nutrients to the developing seed by being small, linear and covered with grey hairs: this reduces water loss and overheating during the summer. Often the seed is quite small and ripens quickly after pollination further reducing the plant’s need for moisture. Packera grows in sites where there is little competition from other vegetation. The seed is adapted to germinate in open conditions, requiring a broad spectrum of light to germinate. In the nursery, the seed is sown on the surface of the soil. Fresh seed needs no stratification."- From the draft protocol for P. macounii, Sustainability in Prisons.[4]


Measurement Range: L: 4-6 mm W: 0.5-1 mm D: 0.5-0.7 mm. Surface: elongate with longitudinal grooves, colored black and tan, short pappus hairs.[4]

Photo Gallery


  1. Integrated Taxonomic Information System. Retrieved from
  2. 2.0 2.1 Klinkenberg, Brian. (Editor) 2020. E-Flora BC: Electronic Atlas of the Plants of British Columbia []. Lab for Advanced Spatial Analysis, Department of Geography, University of British Columbia, Vancouver. [Accessed: 2020-06-03 10:54:09 AM]
  3. 3.0 3.1 Hitchcock, C. L., Cronquist, A., Giblin, D., & Legler, B. et al. (2018). Flora of the Pacific Northwest: an illustrated manual. Seattle: University of Washington Press.
  4. 4.0 4.1 4.2 Elliott, C. (2014, March 3). Retrieved from

Siskiyou Mountain ragwort USDA Plants Database page

Integrated Taxonomic Information System

Jepson Manual Treatment