North America Non-native Plant

Crotalaria Atrorubens

Botanical name: Crotalaria atrorubens

USDA symbol: CRAT5

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

Crotalaria atrorubens: A Mysterious Member of the Rattlebox Family If you’ve stumbled across the name Crotalaria atrorubens in your plant research, you’re likely wondering what exactly this species is and whether it belongs in your garden. Well, you’re not alone in your curiosity – this particular member of the Crotalaria ...

Crotalaria atrorubens: A Mysterious Member of the Rattlebox Family

If you’ve stumbled across the name Crotalaria atrorubens in your plant research, you’re likely wondering what exactly this species is and whether it belongs in your garden. Well, you’re not alone in your curiosity – this particular member of the Crotalaria genus is quite the botanical mystery!

The Challenge of Lesser-Known Species

Crotalaria atrorubens falls into that intriguing category of plants that don’t have widely recognized common names or extensive cultivation information. While the Crotalaria genus – commonly known as rattlebox or rattlepod – contains hundreds of species worldwide, not all of them are well-documented for home gardening purposes.

What We Know About the Crotalaria Family

Before diving into the specifics of C. atrorubens, let’s talk about what we do know about its plant family. Crotalaria species are typically:

  • Members of the legume family (Fabaceae)
  • Known for their distinctive seed pods that rattle when dry
  • Often featuring bright yellow, pea-like flowers
  • Capable of fixing nitrogen in the soil

Geographic Distribution and Native Status

Unfortunately, specific information about where Crotalaria atrorubens naturally occurs is not readily available in standard botanical databases. This lack of clear geographic and native status information makes it difficult to determine whether this species would be appropriate for native plant gardens.

Should You Plant Crotalaria atrorubens?

Here’s where things get a bit tricky. Without clear information about this species’ native range, growing requirements, or potential invasiveness, it’s challenging to make a solid recommendation either way. Here are some important considerations:

Proceed with Caution

  • Unknown origin: Without knowing where this plant is native, you can’t be sure it’s appropriate for your local ecosystem
  • Limited cultivation info: No established growing guidelines means you’d be experimenting
  • Potential confusion: The name might be a synonym or variant that’s not widely recognized

Better Alternatives to Consider

If you’re drawn to the Crotalaria genus, consider these better-documented alternatives that might work in your region:

  • Research native legumes in your area through your local native plant society
  • Consult your regional extension office for appropriate nitrogen-fixing plants
  • Look into well-established native wildflowers with similar ecological benefits

Growing Conditions and Care

Since specific growing requirements for Crotalaria atrorubens aren’t well-documented, we can only make educated guesses based on related species. Most Crotalaria prefer:

  • Full sun exposure
  • Well-draining soil
  • Moderate water needs
  • Warm growing conditions

However, these are generalizations and may not apply to this specific species.

The Bottom Line

While botanical mysteries like Crotalaria atrorubens can be fascinating, they’re not the best choice for most home gardeners. Without clear information about native status, growing requirements, or potential ecological impacts, it’s wiser to choose well-documented native plants that will thrive in your garden and support local wildlife.

If you’re determined to learn more about this species, consider reaching out to botanical gardens, university herbaria, or taxonomic experts who might have additional insights. Sometimes the most rewarding gardening adventures begin with a little detective work!

Remember, the best garden plants are those that are well-suited to your local conditions and support your area’s native ecosystem. When in doubt, native plant societies and extension offices are excellent resources for finding the perfect plants for your space.

Crotalaria Atrorubens

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

Fabales

Family

Fabaceae Lindl. - Pea family

Genus

Crotalaria L. - rattlebox

Species

Crotalaria atrorubens Hochst. ex Benth.

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