North America Native Plant

Whitemargin Oxytheca

Botanical name: Oxytheca emarginata

USDA symbol: OXEM

Life cycle: annual

Habit: forb

Native status: Native to the lower 48 states  

Whitemargin Oxytheca: A Rare California Native That Belongs in the Wild, Not Your Garden Meet the whitemargin oxytheca (Oxytheca emarginata), one of California’s most elusive native plants. While you might be tempted to add this delicate annual to your native plant collection, this little beauty comes with a big responsibility—and ...

Rare plant alert!

Region: Conservation status by state

Status: S2: 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) ⚘

Whitemargin Oxytheca: A Rare California Native That Belongs in the Wild, Not Your Garden

Meet the whitemargin oxytheca (Oxytheca emarginata), one of California’s most elusive native plants. While you might be tempted to add this delicate annual to your native plant collection, this little beauty comes with a big responsibility—and frankly, it’s better left where nature intended it to be.

What Makes Whitemargin Oxytheca Special?

This charming annual forb belongs to California’s exclusive club of rare native plants. As a member of the buckwheat family, whitemargin oxytheca produces tiny, delicate flowers that might seem perfect for a wildflower garden. However, appearances can be deceiving when it comes to conservation.

Unlike the woody shrubs and trees you might be familiar with, this plant is what botanists call a forb—essentially a soft-stemmed, herbaceous plant that completes its entire life cycle in just one growing season. Think of it as nature’s annual flower, but with a much more exclusive guest list.

Where Does It Call Home?

Whitemargin oxytheca is a true California endemic, meaning it exists nowhere else on Earth except within the Golden State’s borders. This limited geographic distribution is already a red flag for conservation concerns, but the story gets more serious from there.

The Conservation Reality Check

Here’s where we need to have a serious conversation. Whitemargin oxytheca carries a Global Conservation Status of S2, which translates to Imperiled. This isn’t just botanical jargon—it means this species is hanging by a thread, with typically only 6 to 20 known occurrences and somewhere between 1,000 to 3,000 individual plants remaining in the wild.

When a plant reaches this level of rarity, every individual matters. That’s why responsible gardeners should resist the urge to cultivate this species, even if seeds or plants become available.

Why You Shouldn’t Plant Whitemargin Oxytheca

While we usually encourage native plant gardening, whitemargin oxytheca falls into a special category that requires a hands-off approach:

  • Its extreme rarity means removing it from wild populations could contribute to its decline
  • We don’t have enough research on its specific growing requirements to cultivate it successfully
  • Conservation efforts should focus on protecting existing wild populations, not home cultivation
  • There are many other beautiful California native annuals that aren’t imperiled

Better Alternatives for Your Native Garden

Instead of seeking out this rare treasure, consider these abundant California native annuals that will give you similar wildflower appeal without conservation concerns:

  • California poppies (Eschscholzia californica)
  • Baby blue eyes (Nemophila menziesii)
  • Clarkia species
  • Lupine species
  • Common buckwheat relatives that aren’t rare

How You Can Help

The best way to support whitemargin oxytheca isn’t by trying to grow it in your garden—it’s by supporting conservation efforts and habitat protection. If you’re passionate about rare plants, consider:

  • Volunteering with native plant societies focused on conservation
  • Supporting habitat preservation organizations in California
  • Choosing abundant native plants for your garden instead
  • Spreading awareness about the importance of protecting rare species

If You Encounter It in the Wild

Should you be lucky enough to spot whitemargin oxytheca during your California adventures, treat it like the botanical treasure it is. Take photos, note the location for scientific databases if appropriate, but please don’t collect seeds or disturb the plants. Every individual is precious for the species’ survival.

The Bigger Picture

Whitemargin oxytheca reminds us that not every native plant is suitable for cultivation—and that’s perfectly okay. Sometimes the most meaningful way to appreciate a species is to ensure it thrives in its natural habitat rather than attempting to domesticate it.

By choosing abundant native plants for our gardens and supporting conservation efforts for rare species like whitemargin oxytheca, we can create beautiful landscapes while being responsible stewards of California’s incredible botanical heritage.

Whitemargin Oxytheca

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Caryophyllidae

Order

Polygonales

Family

Polygonaceae Juss. - Buckwheat family

Genus

Oxytheca Nutt. - oxytheca

Species

Oxytheca emarginata H.M. Hall - whitemargin oxytheca

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