North America Native Plant

Twobristle Rockdaisy

Botanical name: Perityle bisetosa var. bisetosa

USDA symbol: PEBIB

Life cycle: perennial

Habit: subshrub

Native status: Native to the lower 48 states  

Synonyms: Laphamia bisetosa Torr. ex A. Gray (LABI4)   

Twobristle Rockdaisy: A Rare Texas Native Worth Protecting in Your Garden Meet the twobristle rockdaisy (Perityle bisetosa var. bisetosa), a charming little Texas native that’s as tough as it sounds! This delightful perennial herb might not be the showiest plant in the garden center, but it’s got character, resilience, and ...

Rare plant alert!

Region: Conservation status by state

Status: S2T2: Status is uncertain but is somewhere between the following rankings: Imperiled: Extremely rare due to factor(s) making it especially vulnerable to extinction. Typically 6 to 20 occurrences or few remaining individuals (1,000 to 3,000) ⚘ Subspecies or variety is imperiled: Extremely rare due to factor(s) making it especially vulnerable to extinction. Typically 6 to 20 occurrences or few remaining individuals (1,000 to 3,000) ⚘

Twobristle Rockdaisy: A Rare Texas Native Worth Protecting in Your Garden

Meet the twobristle rockdaisy (Perityle bisetosa var. bisetosa), a charming little Texas native that’s as tough as it sounds! This delightful perennial herb might not be the showiest plant in the garden center, but it’s got character, resilience, and an important conservation story that makes it a worthy addition to the right garden.

What Makes Twobristle Rockdaisy Special?

The twobristle rockdaisy is a true Texan through and through, native to the Lone Star State and found nowhere else in the wild. As a perennial forb, it’s built to last – no significant woody growth above ground, but with persistent roots that help it weather tough conditions year after year. You might also see it listed under its scientific synonym, Laphamia bisetosa, in older botanical references.

This little wildflower produces cheerful daisy-like blooms that add a delicate touch to harsh, rocky landscapes where many other plants struggle to survive. Its compact form and drought tolerance make it a perfect candidate for sustainable, low-water gardening.

Where Does It Grow?

Currently, twobristle rockdaisy is found exclusively in Texas, making it a true regional treasure. This limited distribution is part of what makes the plant special – and also why we need to be mindful about its conservation.

A Word About Rarity

Here’s something important every gardener should know: twobristle rockdaisy has a Global Conservation Status of S2T2, which indicates it’s considered rare and potentially vulnerable. This means that while we absolutely encourage growing this beautiful native, it’s crucial to source plants or seeds from reputable native plant nurseries that practice responsible propagation methods. Never collect plants from the wild!

Why Grow Twobristle Rockdaisy?

If you’re lucky enough to garden in Texas and can source this plant responsibly, here’s why you might want to give it a try:

  • Authentic local character: There’s something special about growing plants that truly belong to your specific region
  • Low maintenance: Once established, this drought-tolerant native requires minimal care
  • Pollinator support: The small flowers attract native bees and other beneficial insects
  • Conservation contribution: By growing rare natives, you’re helping preserve genetic diversity
  • Unique garden appeal: Perfect for rock gardens, xeriscapes, and native plant collections

Growing Conditions and Care

Twobristle rockdaisy thrives in USDA hardiness zones 8-10, making it suitable for most of Texas and similar climates. Like many natives from arid regions, it has some specific preferences:

  • Sunlight: Loves full sun exposure
  • Soil: Requires excellent drainage – think rocky, sandy, or gravelly soils
  • Water: Drought tolerant once established; overwatering is more dangerous than underwatering
  • Garden style: Perfect for rock gardens, desert landscapes, and native plant gardens

Planting and Care Tips

Growing twobristle rockdaisy successfully is all about mimicking its natural habitat:

  • Plant in well-draining soil – add gravel or sand to heavy clay if necessary
  • Choose a sunny location with good air circulation
  • Water sparingly, especially once the plant is established
  • Avoid rich, fertile soils that retain moisture
  • Consider pairing with other drought-tolerant Texas natives for a cohesive look

The Bottom Line

Twobristle rockdaisy might not be the easiest plant to find, but for gardeners committed to growing authentic regional natives, it’s a rewarding choice. Its rarity makes it even more precious – you’ll be growing a little piece of Texas botanical heritage while contributing to the conservation of a unique species.

Just remember: source responsibly, provide excellent drainage, and give this tough little Texan the sunny, lean conditions it craves. In return, you’ll have a resilient, low-maintenance native that connects your garden to the natural heritage of the region.

Twobristle Rockdaisy

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Asteridae

Order

Asterales

Family

Asteraceae Bercht. & J. Presl - Aster family

Genus

Perityle Benth. - rockdaisy

Species

Perityle bisetosa (Torr. ex A. Gray) Shinners - twobristle rockdaisy

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