Imagine finding out that a plant you always thought came from down the street actually journeyed across half the world thousands of years ago—that’s the surprising discovery scientists have made about Hawaii’s iconic ʻōhelo blueberries.
These vibrant red berries, deeply cherished by Hawaiian culture and crucial to local birdlife, are known scientifically as Vaccinium. For years, botanists assumed they shared a lineage with North American blueberry species. But a new study published in the American Journal of Botany reveals their true ancestry lies much farther away: temperate East Asia.
“This is a rare pattern among Hawaiian plants,” explains Dr. Peter W. Fritsch, co-senior author and research scientist at the Botanical Research Institute of Texas (BRIT). While most of Hawaii’s native flora arrived from North America or tropical regions, only about 4% originated in temperate East Asia.
The genetic key to this puzzle lay within the DNA of Hawaiian ʻōhelo plants. After comparing them with relatives worldwide, researchers found the closest match was Vaccinium yatabei—a species unique to Japan. This means Hawaii’s blueberries embarked on an extraordinary 4,000-mile journey across the Pacific Ocean roughly 5–7 million years ago.
Hitchhiking with Bird Migrants
But how did they make this epic voyage? The likely culprits are migratory birds that still traverse the North Pacific today. These feathered travelers likely consumed berries from Japan and transported viable seeds in their digestive systems, inadvertently planting ʻōhelo across thousands of miles.
Once in Hawaii, these resilient plants thrived. They seem to have arrived “pre-adapted” for the wet, chilly conditions of high elevations on islands like Kauai—a testament to their ancestors’ ability to survive cold temperate climates. Even more remarkably, they’ve colonized the stark landscapes of fresh lava flows on the youngest island, Hawaiʻi, where few other plants can take root.
Polynesian Expansion and a Return Trip?
The story doesn’t end there. Evidence suggests that Hawaiian ʻōhelo later spread to Southeastern Polynesia, mingling with another blueberry species from a distinct part of their larger group to create hybrids. Intriguingly, the DNA even hints at at least one ʻōhelo specimen making its way back to coastal North America—a rare instance of plants reversing the typical island-to-continent migration pattern.
This timing coincides with Kauaʻi rising from the sea, Hawaii’s oldest major island. Reaching these shores early gave ʻōhelo millions of years to establish themselves before facing competition from other plant newcomers.
The discovery fundamentally changes our understanding of Hawaiian ʻōhelo blueberries, highlighting their remarkable journey and adaptability. It underscores how interconnected ecosystems are across vast distances and reveals the fascinating interplay between plants, animals, and geological history in shaping biodiversity.
