North America Native Plant

Common Tarweed

Botanical name: Centromadia pungens laevis

USDA symbol: CEPUL

Life cycle: annual

Habit: forb

Native status: Native to the lower 48 states  

Synonyms: Hemizonia laevis (D.D. Keck) D.D. Keck (HELA3)  âš˜  Hemizonia pungens (Hook. & Arn.) Torr. & A. Gray ssp. laevis D.D. Keck (HEPUL)   

Common Tarweed: A Hardy California Native Worth Considering If you’re looking to add authentic California character to your native garden, common tarweed (Centromadia pungens laevis) might just be the unsung hero you’ve been searching for. This annual wildflower may not win any beauty contests, but it packs a serious punch ...

Rare plant alert!

Region: Conservation status by state

Status: S3S4T2: Status is uncertain but is somewhere between the following rankings: 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) ⚘ Vulnerable: Either very rare and local throughout its range, found only in a restricted range (even if abundant at some locations), or factors are making it vulnerable to extinction. Typically 21 to 100 occurrences or between 3,000 and 10,000 individuals ⚘ Apparently Secure: Uncommon but not rare, and usually widespread. Possibly cause for longterm concern. Typically more than 100 occurrences in the state or more than 10,000 individuals ⚘

Common Tarweed: A Hardy California Native Worth Considering

If you’re looking to add authentic California character to your native garden, common tarweed (Centromadia pungens laevis) might just be the unsung hero you’ve been searching for. This annual wildflower may not win any beauty contests, but it packs a serious punch when it comes to supporting local wildlife and thriving in tough conditions.

What Is Common Tarweed?

Common tarweed is a native California annual forb that belongs to the sunflower family. As a forb, it’s an herbaceous plant without woody stems, completing its entire life cycle in just one growing season. Don’t let its humble weed moniker fool you – this plant plays an important ecological role in California’s natural landscapes.

You might also see this plant listed under its former scientific names, including Hemizonia laevis or Hemizonia pungens ssp. laevis, as botanists have reclassified it over the years.

Where Does Common Tarweed Grow?

This hardy native calls California home, where it naturally occurs in grasslands, fields, and disturbed areas throughout much of the state. It’s perfectly adapted to California’s Mediterranean climate and seasonal rainfall patterns.

Why Plant Common Tarweed?

While common tarweed might not be the showiest plant in your garden, it offers several compelling reasons to include it in your landscape:

  • Native authenticity: It’s a true California native that supports local ecosystems
  • Pollinator magnet: The small yellow flowers attract native bees, beneficial insects, and butterflies
  • Low maintenance: Once established, it requires minimal care and water
  • Tough survivor: Thrives in poor soils and dry conditions where other plants struggle
  • Late season interest: Blooms in late summer and fall when many other plants are dormant

Important Conservation Note

Before you rush out to plant common tarweed, there’s something important to know: this plant has a conservation status that suggests it may be somewhat uncommon in its natural range. If you choose to grow it, make sure you source seeds or plants from reputable native plant nurseries that practice responsible collection methods. Never collect seeds from wild populations.

Growing Common Tarweed Successfully

The good news is that common tarweed is relatively easy to grow once you understand its preferences:

Ideal Growing Conditions

  • Sunlight: Full sun is essential
  • Soil: Tolerates poor, dry soils; doesn’t need rich garden soil
  • Water: Drought-tolerant once established; overwatering can be harmful
  • Climate: Best suited for USDA zones 8-10, matching California’s Mediterranean climate

Planting and Care Tips

  • Direct sow seeds in fall to mimic natural germination patterns
  • Scatter seeds over prepared soil and lightly rake in
  • Provide minimal supplemental water during establishment
  • Allow plants to self-seed for naturalistic colonies
  • No fertilization needed – this plant prefers lean conditions

Best Garden Settings

Common tarweed shines in:

  • Wildlife and pollinator gardens
  • Native plant landscapes
  • Meadow and grassland restorations
  • Low-water, naturalistic designs
  • Areas where you want authentic California flora

The Bottom Line

Common tarweed may not be the flashiest choice for your garden, but it’s a hardworking native that supports California’s wildlife while asking for very little in return. If you’re creating a naturalistic landscape, restoring habitat, or simply want to grow plants that truly belong in California, this modest annual deserves consideration. Just remember to source it responsibly and let it do what it does best – thrive in conditions that challenge other plants while quietly supporting the web of life around it.

Common Tarweed

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

Centromadia Greene - tarweed

Species

Centromadia pungens (Hook. & Arn.) Greene - common tarweed

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