North America Native Plant

Mexican Bonebract

Botanical name: Sclerocarpus uniserialis var. austrotexanus

USDA symbol: SCUNA

Life cycle: annual

Habit: forb

Native status: Native to the lower 48 states  

Mexican Bonebract: A Hidden Gem for South Texas Native Gardens If you’re looking to add authentic Texas character to your native garden, Mexican bonebract might just be the unsung hero you’ve been searching for. This humble annual wildflower may not win any beauty contests, but it’s got something far more ...

Mexican Bonebract: A Hidden Gem for South Texas Native Gardens

If you’re looking to add authentic Texas character to your native garden, Mexican bonebract might just be the unsung hero you’ve been searching for. This humble annual wildflower may not win any beauty contests, but it’s got something far more valuable: deep Texas roots and a knack for thriving where other plants throw in the towel.

What Exactly Is Mexican Bonebract?

Mexican bonebract (Sclerocarpus uniserialis var. austrotexanus) is a native annual forb that belongs to the sunflower family. Don’t let the fancy botanical name intimidate you – this is simply a herbaceous wildflower that completes its entire life cycle in one growing season. As a forb, it lacks the woody stems of shrubs and trees, instead producing soft, green stems that die back each year.

This Texas native is perfectly adapted to the challenging growing conditions of South Texas, where summer heat and periodic drought are just part of life.

Where Does It Call Home?

Mexican bonebract is exclusively found in Texas, making it a true Lone Star State endemic. Its range is primarily concentrated in South Texas, particularly in the Rio Grande Valley region. This limited distribution makes it a special addition to gardens within its native range.

Why Your Garden (and Local Wildlife) Will Love It

While Mexican bonebract might not have the showy blooms of other wildflowers, it offers several compelling reasons to include it in your native garden:

  • True Texas heritage: Supporting a plant that evolved specifically in your region
  • Pollinator magnet: The small yellow flowers attract native bees and other beneficial insects
  • Low maintenance: Once established, it requires minimal care
  • Drought tolerance: Perfect for water-wise gardening
  • Natural look: Adds authentic wildness to native plant gardens

Growing Mexican Bonebract Successfully

The beauty of Mexican bonebract lies in its simplicity. This tough little annual knows how to take care of itself, but here’s how to give it the best start:

Ideal Growing Conditions

  • Sunlight: Full sun (6+ hours daily)
  • Soil: Well-draining soil – it won’t tolerate soggy conditions
  • Climate zones: USDA Zones 9-10 (South Texas climate)
  • Water: Drought tolerant once established

Planting and Care Tips

  • Direct sow seeds in fall or early spring
  • Scatter seeds over prepared soil and lightly rake in
  • Water gently until germination occurs
  • Once established, water only during extended dry periods
  • Allow plants to go to seed for natural reseeding

Perfect Garden Companions

Mexican bonebract shines brightest when planted alongside other South Texas natives. Consider pairing it with:

  • Bluebonnets for spring color
  • Native grasses like buffalo grass
  • Other drought-tolerant Texas wildflowers
  • Native shrubs for structure and height variation

Is Mexican Bonebract Right for Your Garden?

Mexican bonebract is ideal for gardeners who:

  • Live within its native South Texas range
  • Want to support local ecosystems
  • Appreciate subtle, natural beauty over flashy displays
  • Prefer low-maintenance gardening
  • Are creating wildlife-friendly spaces

However, it might not be the best choice if you’re looking for a showstopper flower or live outside of South Texas, where it may not thrive in non-native conditions.

The Bottom Line

Mexican bonebract may not be the flashiest flower in the garden center, but for South Texas gardeners committed to supporting native ecosystems, it’s a valuable addition. This resilient annual offers authentic regional character, supports local pollinators, and asks for very little in return. Sometimes the best garden companions are the quiet ones that simply belong.

Mexican Bonebract

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

Sclerocarpus Jacq. - bonebract

Species

Sclerocarpus uniserialis (Benth.) Hemsl. - Mexican bonebract

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