North America Non-native Plant

Capetown Grass

Botanical name: Tribolium obliterum

USDA symbol: TROB6

Life cycle: perennial

Habit: grass

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

Capetown Grass: A Mysterious Non-Native Grass Worth Reconsidering Meet Capetown grass (Tribolium obliterum), one of those enigmatic plants that makes you wonder if it’s playing hide and seek with gardeners. This perennial grass has managed to keep a remarkably low profile despite establishing itself in California’s landscape. What We Know ...

Capetown Grass: A Mysterious Non-Native Grass Worth Reconsidering

Meet Capetown grass (Tribolium obliterum), one of those enigmatic plants that makes you wonder if it’s playing hide and seek with gardeners. This perennial grass has managed to keep a remarkably low profile despite establishing itself in California’s landscape.

What We Know (And Don’t Know) About Capetown Grass

Here’s where things get interesting – and a bit frustrating for curious gardeners. Capetown grass is what botanists call a graminoid, which is just a fancy way of saying it’s part of the grass family or closely related grass-like plants. It’s a perennial, meaning it comes back year after year, but beyond that basic information, this plant remains something of a botanical mystery.

The species has established itself as a non-native resident in California, where it reproduces on its own without human intervention. However, there’s a significant gap in our knowledge about its specific growing requirements, appearance, and behavior in garden settings.

Geographic Distribution

Currently, Capetown grass is documented as growing in California, though the extent of its presence and specific habitats within the state aren’t well documented in readily available horticultural sources.

Should You Plant Capetown Grass?

Here’s where we need to pump the brakes a bit. While Capetown grass isn’t currently listed as invasive or noxious, its non-native status combined with the lack of comprehensive information about its behavior makes it a risky choice for responsible gardeners. When we don’t know how a plant might spread or what impact it could have on local ecosystems, it’s wise to err on the side of caution.

Better Native Alternatives

Instead of gambling with the unknown Capetown grass, consider these well-documented native California grasses that will give you reliable results and support local wildlife:

  • Purple needlegrass (Stipa pulchra) – California’s state grass with beautiful purple-tinged seed heads
  • Blue grama grass (Bouteloua gracilis) – Drought-tolerant with distinctive eyelash-like seed heads
  • Buffalo grass (Bouteloua dactyloides) – Low-growing and extremely drought-resistant
  • California fescue (Festuca californica) – Excellent for erosion control and wildlife habitat

The Mystery Factor

The lack of readily available information about Tribolium obliterum raises some important questions. Is it simply understudied, or is there a reason it hasn’t gained popularity in horticulture? Without clear data on its growth habits, potential invasiveness, or garden performance, it’s difficult to recommend this grass with confidence.

Making Informed Garden Choices

When it comes to choosing plants for your garden, information is your best friend. The mystery surrounding Capetown grass serves as a perfect reminder of why it’s important to research plants thoroughly before adding them to your landscape. Well-documented native species not only give you predictable results but also contribute positively to local ecosystems by supporting native wildlife and maintaining biodiversity.

If you’re drawn to the idea of ornamental grasses in your landscape, stick with the tried-and-true native options that local wildlife will thank you for. Your garden will be more successful, and you’ll be contributing to the health of your local ecosystem rather than potentially introducing another non-native species with unknown consequences.

Capetown Grass

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

Tribolium Desv. - tribolium

Species

Tribolium obliterum (Hemsl.) Renvoize - Capetown grass

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