North America Native Plant

Dwarf Dwarf-cudweed

Botanical name: Hesperevax caulescens

USDA symbol: HECA30

Life cycle: annual

Habit: forb

Native status: Native to the lower 48 states  

Synonyms: Evax acaulis Greene, non (Kellogg) Greene (EVAC2)  âš˜  Evax caulescens (Benth.) A. Gray var. humilis (Greene) Jeps. (EVCAH)  âš˜  Evax caulescens (Benth.) A. Gray var. petiolata A. Gray (EVCAP)  âš˜  Evax involucrata Greene (EVIN)   

Dwarf Dwarf-Cudweed: A Rare California Wetland Native Worth Knowing Meet dwarf dwarf-cudweed (Hesperevax caulescens), a tiny but fascinating annual herb that’s as unique as its wonderfully redundant common name suggests. This unassuming little plant might not win any beauty contests, but it plays an important role in California’s specialized wetland ...

Rare plant alert!

Region: Conservation status by state

Status: S3: Status is uncertain but is somewhere between the following rankings: 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 ⚘

Dwarf Dwarf-Cudweed: A Rare California Wetland Native Worth Knowing

Meet dwarf dwarf-cudweed (Hesperevax caulescens), a tiny but fascinating annual herb that’s as unique as its wonderfully redundant common name suggests. This unassuming little plant might not win any beauty contests, but it plays an important role in California’s specialized wetland ecosystems and deserves our attention – and protection.

What Makes This Plant Special?

Dwarf dwarf-cudweed is a small annual forb, meaning it’s a non-woody plant that completes its entire life cycle in one year. Don’t expect towering stems or showy blooms – this little guy stays close to the ground and produces tiny, inconspicuous white to cream-colored flowers surrounded by woolly bracts. It’s the kind of plant that rewards the observant gardener who appreciates subtle beauty and ecological significance over flashy displays.

Where Does It Call Home?

This California endemic has a very limited range, found only within the Golden State’s borders. It’s perfectly adapted to the state’s unique Mediterranean climate and specialized wetland habitats, particularly vernal pools and seasonal wetlands that flood in winter and dry out in summer.

A Word of Caution: This Plant is Rare

Here’s something important to know: dwarf dwarf-cudweed has a Global Conservation Status of S3, which means it’s considered vulnerable. With typically only 21 to 100 known occurrences and between 3,000 to 10,000 individuals in the wild, this little plant is skating on thin ice. If you’re considering adding it to your garden, please only source it responsibly from reputable native plant nurseries that propagate their own stock – never collect from wild populations.

Growing Conditions: Not Your Average Garden Plant

Let’s be honest – dwarf dwarf-cudweed isn’t for everyone. This plant has very specific needs that make it challenging for typical home gardens:

  • Requires seasonal wetland conditions with winter flooding
  • Thrives in full sun exposure
  • Needs clay or heavy soils that retain winter moisture
  • Adapted to Mediterranean climate patterns (wet winters, dry summers)
  • Suitable for USDA hardiness zones 8-10

As an obligate wetland plant, it almost always occurs in wetlands and won’t survive in typical garden beds with regular watering schedules.

Should You Grow Dwarf Dwarf-Cudweed?

Most home gardeners should probably pass on this one, and here’s why: dwarf dwarf-cudweed requires very specialized growing conditions that are difficult to replicate in typical residential landscapes. Unless you’re working on a wetland restoration project, creating a vernal pool garden, or have naturally occurring seasonal wetland conditions on your property, this plant likely won’t thrive.

However, if you’re involved in habitat restoration or conservation gardening and can provide appropriate wetland conditions, dwarf dwarf-cudweed can be a valuable addition to specialized native plant collections.

Wildlife and Pollinator Benefits

While not a showstopper for pollinators, dwarf dwarf-cudweed does provide resources for small beneficial insects. Its tiny flowers attract minute pollinators and other beneficial arthropods, contributing to the complex web of life in wetland ecosystems.

Planting and Care Tips

If you’re determined to grow this rare beauty and can provide suitable conditions:

  • Plant in areas that flood naturally in winter but dry out in summer
  • Ensure full sun exposure
  • Use clay or heavy soils that retain moisture
  • Allow natural seasonal cycles – no summer irrigation needed
  • Source seeds or plants only from reputable native plant nurseries

The Bottom Line

Dwarf dwarf-cudweed is a fascinating piece of California’s natural heritage, but it’s not a plant for casual gardeners. Its rarity, specialized habitat requirements, and conservation status make it better suited for dedicated restoration projects and specialized native plant gardens. If you’re passionate about wetland conservation and can provide appropriate growing conditions, this little plant offers a unique opportunity to support California’s rare flora. Just remember to source responsibly and appreciate its subtle charms – sometimes the most important plants are the ones that whisper rather than shout.

Dwarf Dwarf-cudweed

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

Hesperevax (A. Gray) A. Gray - dwarf-cudweed

Species

Hesperevax caulescens (Benth.) A. Gray - dwarf dwarf-cudweed

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