North America Native Plant

Poison Tree

Botanical name: Semecarpus venenosus

USDA symbol: SEVE6

Life cycle: perennial

Habit: tree

Native status: Native to Pacific Basin excluding Hawaii  

Synonyms: Semecarpus venenosa Volkens, orth. var. (SEVE7)   

Poison Tree: A Beautiful but Dangerous Pacific Native If you’re gardening in the tropical Pacific and come across the poison tree (Semecarpus venenosus), you’ll want to proceed with serious caution. This impressive native tree might catch your eye with its stately presence, but as the name suggests, it’s not exactly ...

Poison Tree: A Beautiful but Dangerous Pacific Native

If you’re gardening in the tropical Pacific and come across the poison tree (Semecarpus venenosus), you’ll want to proceed with serious caution. This impressive native tree might catch your eye with its stately presence, but as the name suggests, it’s not exactly what you’d call garden-friendly for the average homeowner.

What Is the Poison Tree?

The poison tree, known as tonget in Palau, is a large perennial tree native to the Pacific Basin. This substantial woody plant typically grows as a single-trunked tree reaching heights of 13-16 feet or more, making it a commanding presence in any landscape where it’s found naturally.

Botanically speaking, Semecarpus venenosus belongs to the same family as poison ivy and contains similar toxic compounds that can cause severe skin reactions. Despite its dangers, it’s an important part of the native ecosystem in its home range.

Where Does It Grow?

This tropical native is found naturally in Guam and Palau, where it’s adapted to the warm, humid Pacific island climate. As a true Pacific Basin native (excluding Hawaii), it plays an important ecological role in its native habitats.

Should You Plant a Poison Tree?

Here’s where we need to have a frank conversation. Unless you’re an experienced botanist, conservation professional, or have very specific restoration needs, the poison tree probably isn’t the best choice for your garden. Here’s why:

  • Safety concerns: The tree contains urushiol, the same compound found in poison ivy, which can cause severe allergic reactions and skin burns
  • Handling risks: Every part of the plant can be dangerous to touch, making maintenance extremely hazardous
  • Limited appeal: While it has ecological value, it’s not particularly ornamental compared to safer alternatives

Growing Conditions and Care

If you’re in USDA zones 10-12 and have compelling reasons to grow this species (perhaps for habitat restoration), here’s what you need to know:

Climate Requirements

  • Thrives in tropical climates with high humidity
  • Needs consistently warm temperatures year-round
  • Can handle full sun to partial shade

Soil and Water

  • Prefers well-draining soil
  • Moderate water needs once established
  • Adapts to various soil types in its native range

Safety Precautions

  • Always wear protective clothing, gloves, and eye protection
  • Never burn clippings or fallen leaves
  • Keep away from areas where children and pets play
  • Consider professional maintenance rather than DIY care

Wildlife and Ecological Benefits

In its native habitat, the poison tree does provide some ecological benefits. Its flowers can attract native insects, and it serves as part of the natural forest ecosystem. However, these benefits need to be weighed carefully against the safety risks for home gardeners.

Better Alternatives for Pacific Gardeners

If you’re looking for native Pacific trees that won’t send you to the hospital, consider researching other indigenous species from your specific island that offer beauty without the hazard. Many Pacific islands have gorgeous native trees that provide similar ecological benefits without the toxic concerns.

The Bottom Line

While the poison tree has its place in the natural ecosystem of Guam and Palau, it’s definitely not a plant for the average home gardener. The safety risks simply outweigh any potential benefits for most situations. If you’re committed to native Pacific plants, work with local native plant societies or botanists to find safer alternatives that will give you the tropical native look you’re after without the emergency room visits.

Sometimes the best gardening advice is knowing when not to plant something – and the poison tree is definitely one of those times for most of us!

Poison Tree

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

Sapindales

Family

Anacardiaceae R. Br. - Sumac family

Genus

Semecarpus L. f. - semecarpus

Species

Semecarpus venenosus Volkens - poison tree

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