North America Non-native Plant

Kennedy’s Tropical Bent

Botanical name: Bromidium tandilense

USDA symbol: BRTA

Life cycle: annual

Habit: grass

Native status: Non-native, reproduces and persists in the wild in the lower 48 states  

Synonyms: Agrostis kennedyana Beetle (AGKE2)  âš˜  Agrostis tandilensis (Kuntze) Parodi (AGTA)   

Kennedy’s Tropical Bent: A Wetland Grass Worth Knowing About If you’ve ever wondered about those small, unassuming grasses growing in California’s wetland areas, you might have encountered Kennedy’s Tropical Bent. This annual grass has quietly made itself at home in the Golden State, though it’s quite the world traveler with ...

Kennedy’s Tropical Bent: A Wetland Grass Worth Knowing About

If you’ve ever wondered about those small, unassuming grasses growing in California’s wetland areas, you might have encountered Kennedy’s Tropical Bent. This annual grass has quietly made itself at home in the Golden State, though it’s quite the world traveler with roots far from North American soil.

What Exactly Is Kennedy’s Tropical Bent?

Kennedy’s Tropical Bent (Bromidium tandilense) is a small annual grass that belongs to the same family as your lawn grass, but with very different preferences. You might also see it referenced by its scientific synonyms Agrostis kennedyana or Agrostis tandilensis in older botanical texts, which can make identifying this plant a bit like solving a puzzle.

This grass completes its entire life cycle in one growing season, sprouting, flowering, setting seed, and dying all within a year. It’s what botanists call an obligate wetland species, which is a fancy way of saying it really, really loves wet feet.

Where Does This Grass Call Home?

Here’s where things get interesting: Kennedy’s Tropical Bent isn’t actually native to North America at all. This grass originally hails from South America, likely from the Tandil region of Argentina (hence the tandilense in its scientific name). Today, you’ll find it growing wild in California, where it has established itself as a naturalized resident.

What Does It Look Like?

Don’t expect this grass to make a bold statement in your garden. Kennedy’s Tropical Bent is quite modest in appearance, forming small tufts that blend easily into wetland environments. As an annual, it won’t stick around for multiple seasons, but it can self-seed if conditions are right.

Should You Plant Kennedy’s Tropical Bent?

This is where we need to have an honest conversation. While Kennedy’s Tropical Bent isn’t known to be invasive or particularly problematic, it’s also not bringing much to the table for most gardeners. Here’s what to consider:

The Not-So-Compelling Case for Planting It:

  • Limited ornamental value compared to native grasses
  • Very specific wetland requirements that most gardens can’t accommodate
  • As a non-native species, it doesn’t support local ecosystems like native plants do
  • Minimal wildlife benefits for pollinators and other garden visitors

Better Native Alternatives to Consider:

Instead of Kennedy’s Tropical Bent, consider these beautiful native wetland grasses that will better support local wildlife and ecosystems:

  • California bentgrass (Agrostis pallens) – a true California native
  • Saltgrass (Distichlis spicata) – excellent for coastal wetland gardens
  • Alkali sacaton (Sporobolus airoides) – beautiful and drought-tolerant once established

If You’re Determined to Grow It

Should you decide to experiment with Kennedy’s Tropical Bent despite its limitations, here’s what you need to know:

Growing Conditions:

  • Requires consistently moist to wet soil conditions
  • Thrives in wetland environments or bog gardens
  • Likely hardy in mild winter areas (specific USDA zones unclear)
  • Prefers full sun to partial shade

Care Tips:

  • Maintain consistent soil moisture throughout the growing season
  • Allow natural self-seeding if you want it to return next year
  • No special fertilization requirements
  • Monitor for potential spread beyond desired areas

The Bottom Line

Kennedy’s Tropical Bent is one of those plants that’s more interesting from a botanical perspective than a gardening one. While it’s not causing ecological havoc, it’s also not adding much value to your garden compared to the many stunning native alternatives available.

If you’re passionate about wetland restoration or have a specialized bog garden, you might find it useful. For most gardeners, though, choosing native grasses will give you better results and support local wildlife in the process. Sometimes the best gardening advice is knowing when to skip a plant entirely – and this might be one of those times.

Wetland Status

The rule of seasoned gardeners and landscapers is to choose the "right plant for the right place" matching plants to their ideal growing conditions, so they'll thrive with less work and fewer inputs. But the simplicity of this catchphrase conceals how tricky plant selection is. While tags list watering requirements, there's more to the story.

Knowing a plant's wetland status can simplify the process by revealing the interaction between plants, water, and soil. Surprisingly, many popular landscape plants are wetland species! And what may be a wetland plant in one area, in another it might thrive in drier conditions. Also, it helps you make smarter gardening choices and grow healthy plants with less care and feeding, saving you time, frustration, and money while producing an attractive garden with greater ecological benefits.

Regions
Status
Moisture Conditions

Arid West

OBL

Obligate Wetland - Plants with this status almost always occurs in wetlands

Kennedy’s Tropical Bent

Classification

Group

Monocot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Liliopsida - Monocotyledons

Subclass

Commelinidae

Order

Cyperales

Family

Poaceae Barnhart - Grass family

Genus

Bromidium Nees & Meyen - tropical bent

Species

Bromidium tandilense (Kuntze) Rúgolo - Kennedy's Tropical Bent

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