North America Native Plant

Southern Yellow Loosestrife

Botanical name: Lysimachia tonsa

USDA symbol: LYTO2

Life cycle: perennial

Habit: forb

Native status: Native to the lower 48 states  

Synonyms: Lysimachia tonsa (Alph. Wood) Alph. Wood ex Pax & R. Knuth var. simplex (Kearney) R. Knuth ex Engl. (LYTOS)  âš˜  Steironema intermedium Kearney (STIN6)  âš˜  Steironema tonsum (Alph. Wood) E.P. Bicknell ex Britton (STTO5)   

Southern Yellow Loosestrife: A Native Southeastern Wildflower Worth Knowing If you’re passionate about native plants and looking to add some authentic regional character to your garden, southern yellow loosestrife (Lysimachia tonsa) might just be the under-the-radar gem you’ve been searching for. This perennial wildflower represents the kind of authentic native ...

Southern Yellow Loosestrife: A Native Southeastern Wildflower Worth Knowing

If you’re passionate about native plants and looking to add some authentic regional character to your garden, southern yellow loosestrife (Lysimachia tonsa) might just be the under-the-radar gem you’ve been searching for. This perennial wildflower represents the kind of authentic native beauty that makes southeastern gardens truly special.

What Exactly Is Southern Yellow Loosestrife?

Southern yellow loosestrife is a native perennial forb – which is just a fancy way of saying it’s an herbaceous flowering plant without woody stems. Unlike its tree and shrub neighbors, this plant dies back to the ground each winter and emerges fresh each spring, ready to add its unique presence to the landscape.

You might encounter this plant listed under several scientific synonyms in older botanical references, including Steironema tonsum and Steironema intermedium, but Lysimachia tonsa is the accepted name today.

Where Does It Call Home?

This southeastern native has a relatively focused range, naturally occurring across eight states: Alabama, Georgia, Kentucky, North Carolina, South Carolina, Tennessee, Virginia, and West Virginia. If you live within this region, you’re getting the chance to grow a plant that truly belongs in your local ecosystem.

Why Consider Southern Yellow Loosestrife for Your Garden?

The biggest selling point for southern yellow loosestrife is its authentic native status. When you plant native species, you’re:

  • Supporting local wildlife that evolved alongside these plants
  • Choosing plants naturally adapted to your regional climate
  • Reducing the need for excessive watering and fertilization
  • Preserving regional botanical heritage

As a perennial, southern yellow loosestrife offers the added benefit of returning year after year once established, making it a worthwhile long-term investment in your garden’s ecosystem.

The Honest Truth About Growing Information

Here’s where we need to be upfront: southern yellow loosestrife is somewhat of a botanical mystery. Despite its native status and regional distribution, detailed growing information for this specific species is surprisingly limited in readily available sources. This isn’t uncommon with some of our lesser-known native plants that haven’t made it into mainstream gardening circles.

What we do know is that as a member of the Lysimachia genus, it likely shares some characteristics with its better-documented cousins, but we’d recommend approaching this plant with curiosity rather than specific expectations.

A Cautious Recommendation

If you’re interested in growing southern yellow loosestrife, here’s our advice:

  • Source plants or seeds from reputable native plant nurseries within your region
  • Start with a small planting to observe how it performs in your specific garden conditions
  • Connect with local native plant societies who might have hands-on experience with this species
  • Consider it an opportunity to contribute to our collective knowledge about lesser-known natives

Alternative Native Options

If you’re drawn to the idea of native yellow wildflowers but want something with more established growing information, consider these well-documented southeastern natives:

  • Wild bergamot (Monarda fistulosa)
  • Black-eyed susan (Rudbeckia fulgida)
  • Lanceleaf coreopsis (Coreopsis lanceolata)
  • Wild ginger (Asarum canadense) for shadier spots

The Bottom Line

Southern yellow loosestrife represents the kind of native plant that keeps botanical enthusiasts intrigued – it’s authentically local, potentially beneficial to regional ecosystems, but still holds mysteries about its garden performance. If you’re an adventurous gardener within its native range and enjoy being part of the learning process, this could be an exciting addition to your native plant collection.

Just remember to source responsibly, start small, and share your experiences with fellow native plant enthusiasts. Sometimes the most rewarding gardening adventures come from the plants that haven’t yet made it into all the gardening books.

Southern Yellow Loosestrife

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Dilleniidae

Order

Primulales

Family

Primulaceae Batsch - Primrose family

Genus

Lysimachia L. - yellow loosestrife

Species

Lysimachia tonsa (Alph. Wood) Alph. Wood ex Pax & R. Knuth - southern yellow loosestrife

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