North America Non-native Plant

Alyssum Diffusum

Botanical name: Alyssum diffusum

USDA symbol: ALDI11

Native status: Not native but doesn't reproduce and persist in the wild

Alyssum diffusum: The Mystery Plant That Might Not Be What You Think Ever stumbled across a plant name that seems to exist in botanical limbo? Meet Alyssum diffusum – a species that’s about as elusive as a gardener’s perfect weather forecast. If you’re here looking for growing tips and garden ...

Alyssum diffusum: The Mystery Plant That Might Not Be What You Think

Ever stumbled across a plant name that seems to exist in botanical limbo? Meet Alyssum diffusum – a species that’s about as elusive as a gardener’s perfect weather forecast. If you’re here looking for growing tips and garden advice, you might want to grab a cup of tea because we’re about to dive into one of botany’s more puzzling corners.

The Great Plant Detective Story

Here’s the thing about Alyssum diffusum: it’s surprisingly difficult to find reliable information about this particular species. While the genus Alyssum contains many well-known garden favorites, this specific species seems to fly under the radar of most horticultural databases and gardening resources.

This lack of information could mean several things:

  • It might be an extremely rare or localized species
  • The name could be outdated or synonymous with another, better-known species
  • It may be a regional variant that hasn’t been widely studied or cultivated
  • There could be some taxonomic confusion in the plant world (it happens more than you’d think!)

What We Do Know About the Alyssum Family

While Alyssum diffusum remains mysterious, the Alyssum genus is generally known for producing small, fragrant flowers and having a spreading growth habit. Most Alyssum species are part of the mustard family (Brassicaceae) and are typically low-growing, mat-forming plants that work well as groundcover or in rock gardens.

A Word of Caution for Curious Gardeners

If you’ve encountered this plant name somewhere and are considering adding it to your garden, here’s some friendly advice: proceed with extreme caution. Without clear information about its native status, invasive potential, or growing requirements, it’s impossible to recommend whether this plant would be a good choice for your landscape.

Better Alternatives: Native Alyssum-Like Options

Instead of chasing after this botanical ghost, consider these well-documented native alternatives that offer similar aesthetic appeal:

  • Native wildflowers with small, clustered flowers
  • Regional groundcover plants that provide similar garden functions
  • Well-established Alyssum species with known growing requirements

Check with your local native plant society or extension office for species that are truly native to your area and provide proven benefits to local ecosystems.

The Bottom Line

Sometimes in gardening, the most honest answer is we don’t know enough to recommend this plant. Alyssum diffusum falls squarely into this category. Rather than taking a gamble on an unknown species, your garden (and local ecosystem) will be much better served by choosing well-documented native plants with proven track records.

If you’re determined to solve the Alyssum diffusum mystery, consider reaching out to botanical gardens, university extension programs, or professional botanists who might have more specialized knowledge about this elusive species.

Remember: good gardening is often about knowing when not to plant something just as much as knowing what to plant!

Alyssum Diffusum

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

Alyssum L. - madwort

Species

Alyssum diffusum Ten.

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