North America Native Plant

Arrow Poision Plant

Botanical name: Sebastiania bilocularis

USDA symbol: SEBI9

Life cycle: perennial

Habit: shrub

Native status: Native to the lower 48 states  

Synonyms: Sapium biloculare (S. Watson) Pax (SABI4)   

Arrow Poison Plant: A Rare Arizona Native Worth Knowing About Meet the arrow poison plant (Sebastiania bilocularis), a fascinating yet elusive shrub that calls the deserts of Arizona home. Don’t let the dramatic common name fool you – this native beauty is more intriguing than intimidating, though it’s definitely not ...

Rare plant alert!

Region: Conservation status by state

Status: S3S4: 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 ⚘ 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 ⚘

Arrow Poison Plant: A Rare Arizona Native Worth Knowing About

Meet the arrow poison plant (Sebastiania bilocularis), a fascinating yet elusive shrub that calls the deserts of Arizona home. Don’t let the dramatic common name fool you – this native beauty is more intriguing than intimidating, though it’s definitely not your typical garden center find.

What Makes This Plant Special

The arrow poison plant is a true Arizona native, belonging to a small group of plants that have adapted perfectly to the harsh desert conditions of the Southwest. As a perennial shrub, it typically grows as a multi-stemmed woody plant, usually staying under 13-16 feet tall, making it a manageable size for most landscapes.

This plant also goes by the scientific name Sebastiania bilocularis, and you might occasionally see it listed under its synonym Sapium biloculare in older references.

Where You’ll Find It Growing Wild

Currently, the arrow poison plant is documented as growing naturally in Arizona, where it has carved out its niche in the desert ecosystem. Its native range likely extends into parts of Mexico, though specific distribution data is somewhat limited.

A Word About Rarity

Here’s something important to know: the arrow poison plant has a Global Conservation Status of S3S4, which indicates it’s considered somewhat rare to uncommon in its natural habitat. This means that while it’s not critically endangered, it’s not exactly common either. If you’re considering adding this plant to your landscape, please make sure to source it responsibly from reputable native plant nurseries that don’t collect from wild populations.

Garden Potential and Growing Conditions

While specific cultivation information for Sebastiania bilocularis is limited due to its rarity, we can make some educated assumptions based on its native habitat:

  • Likely thrives in USDA hardiness zones 9-10
  • Probably prefers well-draining, sandy or rocky soils
  • Most likely drought-tolerant once established
  • Would fit well in xeriscaping or desert-themed gardens
  • May prefer full sun to partial shade conditions

Is This Plant Right for Your Garden?

The arrow poison plant could be a unique addition to the right garden, particularly if you’re:

  • Creating a native Arizona landscape
  • Interested in supporting local ecosystems
  • Looking for drought-tolerant, low-maintenance plants
  • Wanting to grow something truly uncommon

However, this isn’t a plant for beginners or those looking for immediate gratification. Due to its rarity, finding the arrow poison plant at nurseries will be challenging, and growing information is limited.

Planting and Care Tips

Since specific care information for Sebastiania bilocularis is scarce, here are some general guidelines based on its desert native status:

  • Plant in fall or early spring when temperatures are moderate
  • Ensure excellent drainage – desert natives hate wet feet
  • Water deeply but infrequently once established
  • Avoid fertilizing, as desert plants often prefer lean soils
  • Mulch around the base to retain moisture and suppress weeds

The Bottom Line

The arrow poison plant represents one of those special native species that adds authentic character to southwestern landscapes. While it may not be the easiest plant to find or grow, its rarity makes it all the more special for dedicated native plant enthusiasts.

If you do decide to seek out this unique shrub, remember to source it responsibly and be patient with its establishment. Sometimes the most rewarding plants are those that challenge us to learn something new while supporting our local ecosystems.

For those interested in similar but more readily available options, consider exploring other native Arizona shrubs that might offer similar aesthetic appeal with better availability and growing information.

Arrow Poision Plant

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Rosidae

Order

Euphorbiales

Family

Euphorbiaceae Juss. - Spurge family

Genus

Sebastiania Spreng. - Sebastian-bush

Species

Sebastiania bilocularis S. Watson - arrow poision plant

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