North America Native Plant

Kahili Ridge Yellow Loosestrife

Botanical name: Lysimachia kahiliensis

USDA symbol: LYKA2

Life cycle: perennial

Habit: shrub

Native status: Native to Hawaii  

Kahili Ridge Yellow Loosestrife: A Lost Hawaiian Treasure Meet Kahili Ridge yellow loosestrife (Lysimachia kahiliensis), a Hawaiian native plant that tells one of conservation’s most sobering stories. This perennial shrub once called the islands home, but today it exists only in our botanical records and the hopes of researchers who ...

Rare plant alert!

Region: Conservation status by state

Status: SH: Status is uncertain but is somewhere between the following rankings: Possibly Extinct: Known only from historical occurrences. Still some hope of rediscovery ⚘

Kahili Ridge Yellow Loosestrife: A Lost Hawaiian Treasure

Meet Kahili Ridge yellow loosestrife (Lysimachia kahiliensis), a Hawaiian native plant that tells one of conservation’s most sobering stories. This perennial shrub once called the islands home, but today it exists only in our botanical records and the hopes of researchers who dream of its rediscovery.

A Plant Lost to Time

Here’s the heartbreaking reality: Lysimachia kahiliensis carries a Global Conservation Status of SH, which stands for Possibly Extirpated. In plain English, this means scientists believe this plant may be gone forever from the wild, known only from historical records. There’s still a glimmer of hope for rediscovery, but it’s been missing from its native Hawaiian landscapes for quite some time.

What We Know About This Hawaiian Native

Lysimachia kahiliensis was a perennial shrub native exclusively to Hawaii. As a multi-stemmed woody plant, it typically grew to heights of 13 to 16 feet, though it could sometimes reach taller heights or develop a single stem depending on environmental conditions.

This plant was part of Hawaii’s unique native flora, found nowhere else on Earth. Its geographic distribution was limited to the Hawaiian Islands, making its potential loss even more significant for the state’s biodiversity.

Why You Can’t (and Shouldn’t Try to) Grow It

If you’re hoping to add this plant to your garden, we have to deliver some disappointing news. Since Lysimachia kahiliensis is possibly extirpated, it’s not available through any legitimate nursery or seed source. More importantly, if any specimens were miraculously discovered, they would need to be:

  • Protected in their natural habitat
  • Carefully studied by botanists and conservation experts
  • Used exclusively for species recovery efforts
  • Never harvested for private cultivation

The Bigger Picture

The story of Kahili Ridge yellow loosestrife serves as a powerful reminder of why native plant conservation matters. Hawaii has lost many of its endemic species due to habitat destruction, invasive species, and climate change. Each lost species represents millions of years of unique evolutionary history that can never be replaced.

What You Can Do Instead

While you can’t grow Lysimachia kahiliensis, you can make a difference for Hawaiian native plants that still have a fighting chance:

  • Choose other native Hawaiian plants for your landscape if you live in appropriate zones
  • Support organizations working on native plant conservation in Hawaii
  • Never collect plants from the wild
  • Report any unusual plants you might encounter to local botanical authorities
  • Advocate for habitat protection and restoration

Sometimes the most important gardening lesson isn’t about what to plant, but about understanding what we’ve already lost—and working to ensure we don’t lose any more of these irreplaceable natural treasures.

Kahili Ridge 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 kahiliensis H. St. John - Kahili Ridge 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