North America Native Plant

Spinysepal Eryngo

Botanical name: Eryngium spinosepalum

USDA symbol: ERSP16

Life cycle: biennial

Habit: forb

Native status: Native to the lower 48 states  

Synonyms: Eryngium vaseyi J.M. Coult. & Rose var. globosum Hoover ex Mathias & Constance (ERVAG)   

Spinysepal Eryngo: A Rare California Native Worth Protecting Meet the spinysepal eryngo (Eryngium spinosepalum), one of California’s most elusive native wildflowers. This little-known member of the carrot family is so rare that most gardeners have never heard of it—and that’s exactly why we need to talk about it. What Makes ...

Rare plant alert!

Region: Conservation status by state

Status: S2: Status is uncertain but is somewhere between the following rankings: 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) ⚘

Spinysepal Eryngo: A Rare California Native Worth Protecting

Meet the spinysepal eryngo (Eryngium spinosepalum), one of California’s most elusive native wildflowers. This little-known member of the carrot family is so rare that most gardeners have never heard of it—and that’s exactly why we need to talk about it.

What Makes Spinysepal Eryngo Special

The spinysepal eryngo is a native herbaceous perennial (sometimes biennial) that belongs exclusively to California’s unique flora. As a forb—essentially a non-woody flowering plant—it represents the kind of specialized native species that makes our regional ecosystems so distinctive.

This plant is currently found only in California, making it a true Golden State endemic. However, its distribution is extremely limited, which brings us to an important conservation concern.

A Rare Treasure in Need of Protection

Here’s where things get serious: spinysepal eryngo has a Global Conservation Status of S2, meaning it’s considered Imperiled. In plain English, this means there are likely only 6 to 20 known populations left, with perhaps 1,000 to 3,000 individual plants in the wild. That’s incredibly rare—rarer than many animals we consider endangered.

This rarity status means that if you’re interested in growing spinysepal eryngo, you have a responsibility to source it ethically. Never collect seeds or plants from wild populations, as this could push local populations closer to extinction.

Habitat Preferences

Spinysepal eryngo appears to be a wetland-associated plant, classified as Facultative Wetland in both the Arid West and Western Mountains regions. This means it usually grows in wetland conditions but can occasionally be found in drier areas. This habitat preference gives us clues about its growing requirements, even though specific cultivation information is scarce.

Should You Grow Spinysepal Eryngo?

The short answer is: only if you can source it responsibly and are committed to conservation. Here’s what to consider:

  • Rarity responsibility: With so few populations left, any cultivation should support conservation efforts, not detract from them
  • Sourcing challenges: Finding ethically sourced seeds or plants will be extremely difficult
  • Specialized needs: As a wetland-associated plant, it likely has specific moisture and soil requirements
  • Conservation value: Growing rare natives helps preserve genetic diversity and could support species recovery

Better Alternatives for Most Gardeners

Unless you’re working directly with conservation organizations, consider these more readily available California native alternatives that provide similar ecological benefits:

  • Other Eryngium species that are less rare
  • Native sedges and rushes for wetland gardens
  • Common native forbs that support local pollinators

Supporting Conservation Efforts

The best way most gardeners can help spinysepal eryngo is by:

  • Supporting organizations that work to protect California’s rare plants
  • Creating habitat for common native species
  • Learning about and advocating for rare plant conservation
  • Choosing abundant native plants for home gardens

The Bigger Picture

Spinysepal eryngo reminds us that California’s native plant diversity includes not just the showstoppers like poppies and lupines, but also quiet, specialized species that exist in small numbers. These rare plants are often indicators of healthy, intact ecosystems—and their decline signals broader environmental challenges.

While most of us won’t grow spinysepal eryngo in our gardens, knowing about it helps us appreciate the full spectrum of California’s botanical heritage. Every time we choose native plants for our landscapes, we’re supporting the broader ecosystem that rare species like this one depend on.

Sometimes the best way to love a plant is to admire it from afar and work to protect the wild places where it belongs.

Spinysepal Eryngo

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Rosidae

Order

Apiales

Family

Apiaceae Lindl. - Carrot family

Genus

Eryngium L. - eryngo

Species

Eryngium spinosepalum Mathias - spinysepal eryngo

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