North America Native Plant

Kennebunkport Dewberry

Botanical name: Rubus harmonicus

USDA symbol: RUHA4

Life cycle: perennial

Habit: subshrub

Native status: Native to the lower 48 states  

Kennebunkport Dewberry: Maine’s Rare Native Treasure Meet the Kennebunkport dewberry (Rubus harmonicus), one of Maine’s most elusive native plants. This little-known member of the raspberry family is so rare that it might just be the botanical equivalent of finding a four-leaf clover – except much, much harder to spot! What ...

Rare plant alert!

Region: Conservation status by state

Status: S2?Q: Status is uncertain but is somewhere between the following rankings: Inexact rank: ⚘ Uncertain taxonomy: ⚘ Imperiled: Extremely rare due to factor(s) making it especially vulnerable to extinction. Typically 6 to 20 occurrences or few remaining individuals (1,000 to 3,000) ⚘

Kennebunkport Dewberry: Maine’s Rare Native Treasure

Meet the Kennebunkport dewberry (Rubus harmonicus), one of Maine’s most elusive native plants. This little-known member of the raspberry family is so rare that it might just be the botanical equivalent of finding a four-leaf clover – except much, much harder to spot!

What Makes This Plant Special?

The Kennebunkport dewberry is a perennial shrub that stays refreshingly compact, typically growing under 1.5 feet tall and never exceeding 3 feet at maturity. As part of the Rubus genus, it’s related to raspberries and blackberries, though it has carved out its own unique niche in Maine’s ecosystem.

Where to Find It (If You’re Lucky)

This dewberry is endemic to Maine, making it a true state treasure. Its extremely limited distribution means you won’t stumble across it during a casual nature walk – this plant is genuinely rare and precious.

The Rarity Factor: Why This Matters

Here’s where things get serious: Rubus harmonicus has a Global Conservation Status of S2?Q, which essentially means we’re not entirely sure, but it’s definitely rare and possibly vulnerable. This uncertain status makes it all the more important to protect the populations we know about.

If you’re considering adding this plant to your garden, proceed with extreme caution and responsibility. Only source plants from reputable native plant nurseries that can guarantee their material wasn’t collected from wild populations.

Should You Grow Kennebunkport Dewberry?

The honest answer? Probably not, unless you’re a dedicated native plant conservationist with access to ethically sourced material. Here’s why:

  • Its extreme rarity means wild collection could harm existing populations
  • Limited availability through commercial sources
  • Insufficient data on cultivation requirements
  • May have very specific habitat needs that are difficult to replicate

Better Alternatives for Your Maine Garden

Instead of seeking out this rare dewberry, consider these more readily available native Rubus species that will give you similar benefits:

  • Wild red raspberry (Rubus idaeus)
  • Common dewberry (Rubus flagellaris)
  • Swamp dewberry (Rubus hispidus)

These alternatives will provide food for wildlife, attractive flowers, and that lovely trailing habit that makes dewberries so charming in naturalized areas.

Conservation Considerations

If you do encounter Kennebunkport dewberry in the wild, consider yourself incredibly fortunate – and please don’t disturb it! Instead:

  • Take photos (from a respectful distance)
  • Note the location and report it to local botanists or conservation organizations
  • Help protect the habitat by staying on designated trails
  • Share your sighting with citizen science projects

The Bottom Line

While Kennebunkport dewberry is undoubtedly a fascinating piece of Maine’s botanical heritage, it’s better admired from afar and protected in its natural habitat. For most gardeners, choosing more common native dewberries will provide similar aesthetic and ecological benefits while supporting conservation efforts for truly rare species like Rubus harmonicus.

Sometimes the most meaningful way to appreciate a plant is to ensure it continues thriving in the wild for future generations to discover and wonder about.

Kennebunkport Dewberry

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

Rosales

Family

Rosaceae Juss. - Rose family

Genus

Rubus L. - blackberry

Species

Rubus harmonicus L.H. Bailey - Kennebunkport dewberry

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