North America Native Plant

Island Wallflower

Botanical name: Erysimum insulare suffrutescens

USDA symbol: ERINS

Life cycle: perennial

Habit: subshrub

Native status: Native to the lower 48 states  

Synonyms: Erysimum concinnum Eastw. ssp. suffrutescens Abrams (ERCOS3)  âš˜  Erysimum suffrutescens (Abrams) G. Rossb. (ERSU7)  âš˜  Erysimum suffrutescens (Abrams) G. Rossb. var. grandifolium G. Rossb. (ERSUG)   

Island Wallflower: A Rare California Native Worth Protecting If you’ve stumbled across the name island wallflower in your native plant research, you’ve discovered one of California’s more elusive botanical treasures. Erysimum insulare suffrutescens is a perennial herb that calls the Golden State home, but don’t expect to find it at ...

Rare plant alert!

Region: Conservation status by state

Status: S3T3: 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 ⚘ Subspecies or variety is 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. ⚘

Island Wallflower: A Rare California Native Worth Protecting

If you’ve stumbled across the name island wallflower in your native plant research, you’ve discovered one of California’s more elusive botanical treasures. Erysimum insulare suffrutescens is a perennial herb that calls the Golden State home, but don’t expect to find it at your local nursery anytime soon.

What Makes Island Wallflower Special

Island wallflower belongs to the mustard family and grows as what botanists call a forb – essentially a non-woody flowering plant. As a perennial, it returns year after year, though its exact appearance and growing habits remain something of a mystery in cultivation circles.

This plant goes by several scientific names, including Erysimum concinnum ssp. suffrutescens and Erysimum suffrutescens, which can make tracking down information about it quite the detective story!

Where Does Island Wallflower Grow?

Island wallflower is native to California and grows nowhere else in the world. This limited geographic distribution is part of what makes it so special – and so rare.

The Rarity Factor: Why You Should Care

Here’s where things get serious. Island wallflower has a conservation status of S3T3, which indicates it’s uncommon to rare in its native range. This isn’t a plant you should casually dig up from the wild or purchase from questionable sources.

If you’re determined to grow this rare beauty, you’ll need to:

  • Source seeds or plants only from reputable native plant nurseries
  • Verify that any material has been responsibly propagated, not wild-collected
  • Consider whether you have the expertise to successfully cultivate a rare species

The Cultivation Challenge

Unfortunately, detailed growing information for island wallflower is scarce. We know it’s a California native perennial, but specifics about soil preferences, water needs, sun exposure, and hardiness zones aren’t well-documented in gardening literature.

This lack of cultivation information presents a real challenge for home gardeners. Without knowing its preferred growing conditions, successfully establishing this plant becomes a bit of a gamble.

Should You Plant Island Wallflower?

Given its rarity and the limited information available about cultivation, island wallflower might not be the best choice for most gardeners. Here’s what to consider:

Reasons to be cautious:

  • Limited availability from reputable sources
  • Lack of detailed growing information
  • Rare conservation status requires responsible handling
  • May be difficult to establish without specialized knowledge

Better Alternatives for Your Garden

If you’re drawn to California native wallflowers, consider these better-documented alternatives:

  • Western wallflower (Erysimum capitatum) – more widely available and well-understood
  • Point Reyes wallflower (Erysimum concinnum) – another California native with better cultivation information
  • Other native mustard family plants that support local ecosystems

The Bottom Line

Island wallflower represents the fascinating diversity of California’s native flora, but it’s probably better admired from afar than grown in most home gardens. If you’re passionate about rare plant conservation, consider supporting organizations that work to protect these species in their natural habitats.

For most gardeners, choosing well-documented native alternatives will provide better results while still supporting local wildlife and maintaining the character of California’s natural landscapes. Sometimes the best way to love a rare plant is to let it thrive where it belongs – in the wild.

Island Wallflower

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Dilleniidae

Order

Capparales

Family

Brassicaceae Burnett - Mustard family

Genus

Erysimum L. - wallflower

Species

Erysimum insulare Greene - island wallflower

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