North America Native Plant

Twobristle Rockdaisy

Botanical name: Perityle bisetosa var. scalaris

USDA symbol: PEBIS

Life cycle: perennial

Habit: subshrub

Native status: Native to the lower 48 states  

Twobristle Rockdaisy: A Rare Texas Native Worth Protecting Meet the twobristle rockdaisy (Perityle bisetosa var. scalaris), a charming little native that’s about as exclusive as plants get. This herbaceous perennial is so rare that finding one in the wild is like discovering a botanical treasure – which, in many ways, ...

Rare plant alert!

Region: Conservation status by state

Status: S2T1: Status is uncertain but is somewhere between the following rankings: Subspecies or variety is critically Imperiled: Extremely rare due to factor(s) making it especially vulnerable to extinction. Typically 5 or fewer occurrences or very few remaining individuals (<1,000) ⚘ 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

Meet the twobristle rockdaisy (Perityle bisetosa var. scalaris), a charming little native that’s about as exclusive as plants get. This herbaceous perennial is so rare that finding one in the wild is like discovering a botanical treasure – which, in many ways, it actually is!

Where You’ll Find This Texas Gem

The twobristle rockdaisy calls Texas home, where it has quietly made its living as a true native species. As part of the rock daisy family, this plant has adapted to the unique conditions of the Lone Star State, though it’s become increasingly uncommon over time.

A Rare Beauty That Needs Our Help

Here’s the thing about twobristle rockdaisy that every gardener should know: it’s genuinely rare. With a Global Conservation Status of S2T1, this plant is considered uncommon to rare throughout its range. This means that while it might be tempting to add this native beauty to your garden, we need to be extra thoughtful about how we go about it.

If you’re determined to grow this special native, please – and we can’t stress this enough – only source it from reputable native plant nurseries that propagate their stock responsibly. Never collect from wild populations, as this could further threaten an already vulnerable species.

What Makes This Plant Special

As a herbaceous perennial, the twobristle rockdaisy is what botanists call a forb – basically a soft-stemmed plant that lacks the woody tissue of shrubs and trees. True to its rock daisy heritage, it likely thrives in the kind of rocky, well-draining conditions that many Texas natives love.

The plant returns year after year, making it a potentially wonderful addition to native plant gardens focused on Texas species. However, because of its rarity, detailed information about its specific growing requirements, mature size, and garden performance is limited.

Growing Twobristle Rockdaisy Responsibly

If you’re lucky enough to find responsibly sourced twobristle rockdaisy plants, here’s what we know about growing rock daisies in general:

  • They typically prefer well-draining, rocky or sandy soils
  • Most rock daisies handle drought conditions well once established
  • They often thrive in sunny locations
  • Good drainage is usually essential to prevent root rot

Since specific care information for this variety is limited, it’s best to consult with native plant experts in Texas who may have experience with this particular species.

Supporting Conservation Through Gardening

While twobristle rockdaisy might be challenging to find and grow, there are plenty of other Texas natives that can give you that rock daisy charm while supporting local ecosystems. Consider looking into other Perityle species or similar native wildflowers that are more readily available and less conservation-sensitive.

Sometimes the best way to honor a rare plant like twobristle rockdaisy is to create habitat for it by growing its more common relatives and supporting organizations that work to protect Texas’s native plant communities.

Remember: every native plant in our gardens is a small victory for biodiversity, but rare species like twobristle rockdaisy remind us that some botanical treasures need extra care and respect.

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