Non-native Plants

Hydnocarpus

Hydnocarpus anthelminticus

USDA symbol: HYAN4

perennial shrub

Pacific Basin excluding Hawaii: non-native, naturalized

If you’ve stumbled across the name hydnocarpus in your plant research, you’ve discovered one of the more enigmatic members of the tropical shrub world. Hydnocarpus anthelminticus is a perennial shrub that’s managed to fly somewhat under the radar in mainstream gardening circles, and there’s a good reason for that – ...

Hydnocarpus: A Mysterious Tropical Shrub Worth Knowing About

If you’ve stumbled across the name hydnocarpus in your plant research, you’ve discovered one of the more enigmatic members of the tropical shrub world. Hydnocarpus anthelminticus is a perennial shrub that’s managed to fly somewhat under the radar in mainstream gardening circles, and there’s a good reason for that – it’s not exactly your typical backyard plant.

What Exactly Is Hydnocarpus?

Hydnocarpus anthelminticus (also known by its botanical synonyms Hydnocarpus anthelminthicus and Hydnocarpus anthelminthica) is a multi-stemmed woody shrub that typically stays under 13-16 feet tall, though it can occasionally grow taller or develop a single stem depending on environmental conditions. Think of it as nature’s way of keeping you guessing!

Where Does It Come From?

This shrub is not native to the continental United States. Instead, it has established itself as a non-native species in parts of the Pacific Basin, specifically in Guam and Palau, where it reproduces naturally without human intervention. The plant has managed to persist in these tropical island environments, suggesting it’s quite adaptable to warm, humid conditions.

  • Species observed
  • No observations

Should You Consider Growing Hydnocarpus?

Here’s where things get interesting (and a bit challenging). While hydnocarpus isn’t listed as invasive or noxious, there’s remarkably little information available about its cultivation requirements, aesthetic qualities, or garden performance. This makes it something of a gardening wild card.

If you’re considering this plant, here are some factors to keep in mind:

  • Limited cultivation information makes it difficult to predict success
  • Likely requires tropical or subtropical conditions
  • Unknown wildlife and pollinator benefits
  • Specific growing requirements are not well-documented

Growing Conditions and Care

Unfortunately, specific growing conditions for Hydnocarpus anthelminticus remain largely unknown in cultivation. Based on its natural distribution in tropical Pacific islands, we can make some educated guesses:

  • Warm, humid climate preferences
  • Likely frost-sensitive
  • Probably requires consistent moisture
  • USDA hardiness zones unknown

Consider Native Alternatives

Given the limited information about hydnocarpus and its non-native status, you might want to consider native shrub alternatives that offer similar growth habits and better-understood cultivation requirements. Native plants provide proven benefits to local wildlife, require less guesswork in care, and are typically better adapted to your local climate conditions.

Some native shrub options to explore include species native to your specific region that offer reliable performance and ecological benefits.

The Bottom Line

Hydnocarpus anthelminticus represents one of those intriguing plant mysteries that pop up in botanical catalogs from time to time. While it’s not problematic as an invasive species, the lack of cultivation information makes it a risky choice for most home gardeners. If you’re drawn to unusual tropical shrubs, you might be better served by choosing plants with well-documented growing requirements and proven garden performance.

Sometimes the most responsible gardening decision is knowing when a plant might be better admired from afar rather than attempted in your own landscape!

Hydnocarpus anthelminticus is also known as...

Often we refer to plants by their common names. When shopping for plants the scientific name is the best way to positively identify the plant species you desire. But some plants have more than one name! While it doesn't happen often, nurseries might display one name while you're searching for another. Hydnocarpus anthelminticus is also known as:

Hydnocarpus anthelminthicus Pierre ex , orth. var. | USDA symbol: HYAN10
Hydnocarpus anthelminthica Pierre ex , orth. var. | USDA symbol: HYAN9

Why do some plants have more than one name? Over time plant species may be renamed for a few reasons:

  1. Botanists in different regions named the same plant without knowing it had already been classified.
  2. A species was reclassified after scientific advances in, for example, DNA analysis.
  3. Slight variations within a species are sometimes mistakenly identified as entirely new species.

Classification

Group: Dicot
Kingdom: Plantae - Plants
Subkingdom: Tracheobionta - Vascular plants
Superdivision: Spermatophyta - Seed plants
Division: Magnoliophyta - Flowering plants
Class: Magnoliopsida - Dicotyledons
Subclass: Dilleniidae
Order: Violales
Family: Flacourtiaceae Rich. ex DC. - Flacourtia family
Genus: Hydnocarpus Gaertn. - hydnocarpus

Species: Hydnocarpus anthelminticus Pierre ex Laness. - hydnocarpus

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