North America Non-native Plant

Prosopis Castellanosii

Botanical name: Prosopis castellanosii

USDA symbol: PRCA12

Native status: Not native but doesn't reproduce and persist in the wild

Prosopis castellanosii: A Plant to Avoid in Your Garden If you’ve come across the name Prosopis castellanosii in your plant research, you might be wondering whether this mysterious member of the legume family deserves a spot in your landscape. The short answer? Probably not, and here’s why this little-known plant ...

Noxious plant alert!

Prosopis castellanosii: A Plant to Avoid in Your Garden

If you’ve come across the name Prosopis castellanosii in your plant research, you might be wondering whether this mysterious member of the legume family deserves a spot in your landscape. The short answer? Probably not, and here’s why this little-known plant should stay off your gardening wish list.

What We Know (And Don’t Know) About This Plant

Prosopis castellanosii is something of an enigma in the gardening world. While it belongs to the Prosopis genus – commonly known as mesquites – specific information about this particular species is surprisingly scarce. What we do know is concerning: it’s classified as a noxious weed in the United States, which immediately raises red flags for any responsible gardener.

The lack of readily available information about common names, native range, and basic growing characteristics suggests this isn’t a plant that’s widely cultivated or studied. In the plant world, this kind of obscurity often indicates either a very specialized species or one that’s problematic enough that most gardeners and researchers steer clear.

The Noxious Weed Problem

Here’s the most important thing you need to know: Prosopis castellanosii is listed as noxious in the United States. This designation isn’t handed out lightly – it means the plant is considered harmful to agriculture, ecosystems, or human health. Noxious weeds can:

  • Outcompete native plants for resources
  • Alter soil chemistry and ecosystem dynamics
  • Create monocultures that reduce biodiversity
  • Be difficult or impossible to remove once established

Given this classification, we strongly recommend against planting Prosopis castellanosii in your garden, no matter how curious you might be about this mysterious species.

Geographic Distribution Mystery

Unfortunately, specific information about where Prosopis castellanosii naturally occurs is not readily available. However, given the naming convention and what we know about other Prosopis species, it’s likely native to South or Central America. The fact that it’s considered noxious in the United States suggests it’s not native here and has proven problematic when introduced.

Better Alternatives for Your Garden

Instead of risking the ecological and legal headaches that come with noxious weeds, consider these native alternatives that offer similar benefits without the baggage:

  • Native leguminous trees: Black locust (Robinia pseudoacacia) in appropriate regions
  • Native shrubs: Leadplant (Amorpha canescens) or false indigo species
  • Native wildflowers: Wild lupine (Lupinus perennis) or other native legumes

These alternatives will provide nitrogen fixation, wildlife benefits, and aesthetic appeal without the risk of ecological disruption.

The Bottom Line

Sometimes in gardening, the most responsible choice is to say no thanks to a particular plant. Prosopis castellanosii falls squarely into this category. Its noxious status, combined with the lack of reliable growing information and potential ecological risks, makes it a poor choice for any garden.

Instead, focus your energy on well-documented native plants that will thrive in your specific region while supporting local wildlife and ecosystems. Your garden – and your local environment – will thank you for making the responsible choice.

Remember, great gardening isn’t just about growing beautiful plants; it’s about making choices that benefit the broader ecological community. In this case, leaving Prosopis castellanosii out of your landscape is definitely the way to go.

Prosopis Castellanosii

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

Fabales

Family

Fabaceae Lindl. - Pea family

Genus

Prosopis L. - mesquite

Species

Prosopis castellanosii Burkart

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