North America Native Plant

Lewis’ Groundsel

Botanical name: Packera eurycephala var. lewisrosei

USDA symbol: PAEUL

Life cycle: perennial

Habit: subshrub

Native status: Native to the lower 48 states  

Synonyms: Senecio eurycephalus Torr. & A. Gray var. lewisrosei (J.T. Howell) T.M. Barkley (SEEUL)  ⚘  Senecio lewisrosei J.T. Howell (SELE11)   

Lewis’ Groundsel: A Rare California Native Worth Protecting Meet Lewis’ groundsel (Packera eurycephala var. lewisrosei), a little-known perennial wildflower that represents one of California’s botanical treasures. This herbaceous native might not be a household name, but it deserves recognition for its rarity and ecological importance in the Golden State’s diverse ...

Rare plant alert!

Region: Conservation status by state

Status: S4T2: Status is uncertain but is somewhere between the following rankings: Subspecies or variety is imperiled: Extremely rare due to factor(s) making it especially vulnerable to extinction. Typically 6 to 20 occurrences or few remaining individuals (1,000 to 3,000) ⚘ Apparently Secure: Uncommon but not rare, and usually widespread. Possibly cause for longterm concern. Typically more than 100 occurrences in the state or more than 10,000 individuals ⚘

Lewis’ Groundsel: A Rare California Native Worth Protecting

Meet Lewis’ groundsel (Packera eurycephala var. lewisrosei), a little-known perennial wildflower that represents one of California’s botanical treasures. This herbaceous native might not be a household name, but it deserves recognition for its rarity and ecological importance in the Golden State’s diverse plant communities.

What Makes Lewis’ Groundsel Special

Lewis’ groundsel is a perennial forb—essentially a soft-stemmed flowering plant that comes back year after year without developing woody tissue like shrubs or trees. As a member of the sunflower family (Asteraceae), it shares lineage with daisies, asters, and other familiar garden favorites, though this particular variety has carved out its own unique niche in California’s landscape.

You might also encounter this plant in older botanical references under its former names, including Senecio eurycephalus var. lewisrosei or Senecio lewisrosei, as botanical classification has evolved over time.

Where to Find This Rare Beauty

Lewis’ groundsel calls California home and is found nowhere else in the world. This endemic status makes it particularly precious from a conservation standpoint—if we lose it in California, we lose it everywhere.

A Conservation Concern

Here’s where things get serious: Lewis’ groundsel carries a Global Conservation Status of S4T2, indicating it’s considered a rare subspecific taxon that needs our attention. This rarity status means that while the plant isn’t immediately facing extinction, its limited distribution and specialized habitat requirements make it vulnerable to environmental changes, development, and other threats.

If you’re a conservation-minded gardener who wants to grow native California plants, it’s crucial to understand that this isn’t your typical garden center find—and that’s probably for the best.

Should You Grow Lewis’ Groundsel?

The short answer is: probably not, unless you’re working with conservation professionals. Here’s why:

  • Its rarity means wild populations should be left undisturbed
  • Seeds or plants should never be collected from wild populations
  • Commercial availability is extremely limited or non-existent
  • Specialized growing requirements are not well-documented

However, if you’re passionate about supporting rare California natives and have access to responsibly sourced material through botanical gardens, conservation organizations, or specialized native plant societies, Lewis’ groundsel could be a meaningful addition to a conservation-focused garden.

Supporting California’s Rare Plants

Even if you can’t grow Lewis’ groundsel in your garden, you can still support California’s rare plant conservation efforts:

  • Choose other native California wildflowers and perennials for your garden
  • Support organizations working to protect rare plant habitats
  • Participate in citizen science projects that monitor rare plant populations
  • Advocate for habitat protection in your community

Alternative California Natives to Consider

While Lewis’ groundsel might be off-limits for most home gardens, California offers plenty of other beautiful native plants that can bring similar ecological benefits to your landscape. Consider other California native perennials that support pollinators and wildlife while being more readily available through ethical sources.

Every garden can be a small sanctuary for native plants, even if it doesn’t include the rarest species. By choosing widely available natives, you’re still contributing to habitat connectivity and supporting the incredible biodiversity that makes California’s flora so special.

Remember: sometimes the best way to love a rare plant is to admire it from a distance and ensure its wild populations remain healthy for future generations to discover and appreciate.

Lewis’ Groundsel

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Asteridae

Order

Asterales

Family

Asteraceae Bercht. & J. Presl - Aster family

Genus

Packera Á. Löve & D. Löve - ragwort

Species

Packera eurycephala (Torr. & A. Gray) W.A. Weber & Á. Löve - widehead groundsel

Plant data source: USDA, NRCS 2025. The PLANTS Database. https://plants.usda.gov,. 2/25/2025. National Plant Data Team, Greensboro, NC USA