North America Non-native Plant

Perennial Horsegram

Botanical name: Macrotyloma axillare var. axillare

USDA symbol: MAAXA

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

Synonyms: Dolichos axillaris E. Mey. (DOAX2)   

Perennial Horsegram: A Lesser-Known Legume Worth Learning About If you’ve stumbled across the name perennial horsegram (Macrotyloma axillare var. axillare) in your plant research, you’re probably wondering what exactly this plant is and whether it belongs in your garden. You’re not alone – this particular variety is something of a ...

Perennial Horsegram: A Lesser-Known Legume Worth Learning About

If you’ve stumbled across the name perennial horsegram (Macrotyloma axillare var. axillare) in your plant research, you’re probably wondering what exactly this plant is and whether it belongs in your garden. You’re not alone – this particular variety is something of a mystery in the gardening world, with limited information available even to plant enthusiasts and researchers.

What We Know About Perennial Horsegram

Perennial horsegram belongs to the legume family, which immediately tells us a few useful things. Like other legumes, it likely has the ability to fix nitrogen in the soil through a symbiotic relationship with bacteria in its roots – a trait that can benefit surrounding plants. You might also see this plant referenced by its synonym, Dolichos axillaris.

The perennial part of its common name suggests this plant returns year after year, rather than completing its life cycle in a single season like annual crops. However, beyond these basic characteristics, detailed information about this specific variety remains surprisingly scarce.

Geographic Distribution and Native Status

One of the biggest challenges with perennial horsegram is determining exactly where it naturally occurs and whether it might be suitable for North American gardens. The limited available information suggests connections to African regions, but without clear documentation of its native range, it’s difficult to make informed recommendations about cultivation.

Garden Considerations

Here’s where things get tricky for gardeners. With so little documented information about this plant’s:

  • Hardiness zones and cold tolerance
  • Mature size and growth habit
  • Specific growing requirements
  • Potential invasive tendencies
  • Wildlife and pollinator benefits

It becomes challenging to recommend whether you should add it to your landscape. While the mystery might be intriguing, most gardeners are better served by choosing plants with well-documented characteristics and known benefits.

Better Alternatives for Your Garden

If you’re drawn to the idea of growing a nitrogen-fixing legume with perennial characteristics, consider these well-documented alternatives that offer similar benefits:

  • Wild bergamot and other native wildflowers that support pollinators
  • Native clover species for ground cover and soil improvement
  • Wild lupines, which are spectacular native legumes
  • Partridge pea, an annual native legume that self-seeds readily

The Bottom Line

While perennial horsegram might sound intriguing, the lack of reliable cultivation information makes it a risky choice for most gardeners. Without knowing its hardiness, mature size, growing requirements, or potential for becoming invasive, you could end up with an expensive experiment that doesn’t thrive – or worse, one that thrives too well in the wrong way.

Your garden space and time are valuable resources. Consider focusing on native plants with documented benefits and established growing guidelines. These plants are more likely to reward your efforts with reliable growth, clear ecological benefits, and the satisfaction of supporting local wildlife.

If you’re specifically interested in lesser-known legumes, connect with botanical gardens, university extension services, or specialized plant societies who might have more detailed information about unusual varieties like perennial horsegram.

Perennial Horsegram

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

Macrotyloma (Wight & Arn.) Verdc. - macrotyloma

Species

Macrotyloma axillare (E. Mey.) Verdc. - perennial horsegram

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