North America Non-native Plant

Ethiopian Rattlebox

Botanical name: Crotalaria brevidens var. brevidens

USDA symbol: CRBRB

Life cycle: annual

Habit: forb

Native status: Non-native, reproduces and persists in the wild in Hawaii âš˜ Non-native, reproduces and persists in the wild in Puerto Rico  

Ethiopian Rattlebox: A Lesser-Known Annual Worth Understanding Meet the Ethiopian rattlebox (Crotalaria brevidens var. brevidens), a somewhat mysterious annual plant that has quietly established itself in a few corners of the United States. While it might not be the most famous member of the gardening world, this little forb has ...

Ethiopian Rattlebox: A Lesser-Known Annual Worth Understanding

Meet the Ethiopian rattlebox (Crotalaria brevidens var. brevidens), a somewhat mysterious annual plant that has quietly established itself in a few corners of the United States. While it might not be the most famous member of the gardening world, this little forb has an interesting story to tell.

What Exactly Is Ethiopian Rattlebox?

Ethiopian rattlebox is an annual forb, which is just a fancy way of saying it’s a non-woody plant that completes its entire life cycle in one growing season. As a forb, it lacks significant woody tissue and keeps its growing points (those important buds that help it survive) right at or below ground level.

The name gives us a clue about its origins – this plant likely hails from Africa, specifically the Ethiopian region, though it has since traveled far from home.

Where You’ll Find It Growing

Currently, Ethiopian rattlebox has established populations in Hawaii and Puerto Rico, where it reproduces on its own without human intervention. It’s what botanists call naturalized – essentially, it has made itself at home in these locations and persists year after year, even though it’s not originally from there.

Should You Consider Growing It?

Here’s where things get a bit tricky. Ethiopian rattlebox falls into that gray area of gardening – it’s not native to the continental United States, but it’s also not currently listed as invasive or problematic. However, since we don’t have complete information about its potential impact on local ecosystems, a cautious approach is probably wise.

Better Native Alternatives

If you’re drawn to the idea of annual forbs in your garden, consider exploring native alternatives that will better support your local ecosystem:

  • Native wildflowers that bloom seasonally
  • Regional native annuals that attract local pollinators
  • Indigenous forbs that provide food for native wildlife

Growing Conditions and Care

While specific growing information for Ethiopian rattlebox is limited, most Crotalaria species generally prefer:

  • Well-draining soils
  • Full sun to partial shade
  • Moderate water requirements
  • Warm growing conditions

As an annual, it will complete its full growth cycle in one season, so you’d need to replant or allow it to self-seed each year.

The Bottom Line

Ethiopian rattlebox remains something of an enigma in the gardening world. While it’s not necessarily problematic, the lack of detailed information about its ecological impact means it’s probably not the best choice for most home gardeners. Instead, why not explore the wonderful world of native plants that will definitely benefit your local environment?

If you’re curious about forbs and annual wildflowers, reach out to your local native plant society or extension office – they’ll have great suggestions for plants that are both beautiful and ecologically beneficial in your specific region.

Ethiopian Rattlebox

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 brevidens Benth. - Ethiopian rattlebox

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