North America Native Plant

San Gabriel Ragwort

Botanical name: Senecio astephanus

USDA symbol: SEAS2

Life cycle: perennial

Habit: forb

Native status: Native to the lower 48 states  

San Gabriel Ragwort: A Rare California Native Worth Knowing Meet the San Gabriel ragwort (Senecio astephanus), a little-known California native that deserves a spot on every native plant enthusiast’s radar. This perennial forb might not be as famous as its cousins in the vast Senecio family, but it holds a ...

Rare plant alert!

Region: Conservation status by state

Status: S3: Status is uncertain but is somewhere between the following rankings: Vulnerable: Either very rare and local throughout its range, found only in a restricted range (even if abundant at some locations), or factors are making it vulnerable to extinction. Typically 21 to 100 occurrences or between 3,000 and 10,000 individuals ⚘

San Gabriel Ragwort: A Rare California Native Worth Knowing

Meet the San Gabriel ragwort (Senecio astephanus), a little-known California native that deserves a spot on every native plant enthusiast’s radar. This perennial forb might not be as famous as its cousins in the vast Senecio family, but it holds a special place in California’s botanical heritage.

A True California Original

San Gabriel ragwort is a proud native of California, calling the Golden State home exclusively within the lower 48 states. This herbaceous perennial belongs to the forb category, meaning it’s a non-woody flowering plant that returns year after year, storing energy in its root system through winter months.

You’ll find this species naturally occurring in California, though its exact distribution within the state requires more detailed study. As with many specialized native plants, it likely occupies specific ecological niches that have supported its unique evolution.

Conservation Alert: Handle with Care

Here’s something important every gardener should know: San Gabriel ragwort carries a Global Conservation Status of S3, which translates to Vulnerable. This means the species faces real challenges in the wild, with typically only 21 to 100 known occurrences or between 3,000 and 10,000 individual plants existing.

What does this mean for gardeners? If you’re interested in growing San Gabriel ragwort, you’ll want to be extra careful about sourcing:

  • Only purchase from reputable native plant nurseries that grow from ethically collected seed
  • Never collect plants or seeds from wild populations
  • Consider participating in conservation efforts or seed collection programs led by botanical institutions
  • Help spread awareness about this vulnerable species

Garden Potential and Growing Insights

While specific growing information for Senecio astephanus is limited in available literature, we can draw some educated conclusions from its family characteristics and native habitat. As a member of the Senecio genus (part of the sunflower family), it likely produces cheerful yellow flowers that could add native charm to California gardens.

Being a California native perennial forb, San Gabriel ragwort probably prefers:

  • Well-draining soils typical of California’s Mediterranean climate
  • Moderate to low water requirements once established
  • Full sun to partial shade conditions
  • Minimal fertilization, as most natives prefer lean soils

The Bigger Picture

Growing San Gabriel ragwort isn’t just about adding another plant to your garden—it’s about conservation in action. Native plants like this one support local ecosystems in ways we’re still discovering. They’ve co-evolved with local wildlife, soil microorganisms, and climate patterns over thousands of years.

While we don’t have specific data on San Gabriel ragwort’s wildlife benefits, plants in the Senecio family often support native pollinators and provide food sources for specialized insects that, in turn, feed birds and other wildlife.

A Call for Citizen Science

One of the most exciting aspects of working with lesser-known native plants like San Gabriel ragwort is the opportunity to contribute to scientific knowledge. If you do grow this species, consider:

  • Documenting its growth habits, flowering times, and preferred conditions
  • Photographing visiting pollinators or other wildlife interactions
  • Connecting with local native plant societies or botanical gardens
  • Sharing your experiences with conservation organizations

The Bottom Line

San Gabriel ragwort represents both an opportunity and a responsibility for California gardeners. Its vulnerable status means we need to approach it with respect and care, but its native heritage makes it a valuable addition to conservation-minded landscapes.

If you’re drawn to growing rare natives and supporting biodiversity, San Gabriel ragwort could be a meaningful choice—just remember to source responsibly and treat this vulnerable species with the care it deserves. After all, every garden that successfully grows rare natives like this one becomes a small but important refuge for California’s botanical heritage.

San Gabriel Ragwort

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

Senecio L. - ragwort

Species

Senecio astephanus Greene - San Gabriel ragwort

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