Colombia's Red River: The Mysterious Phenomenon

The Liquid Rainbow of Serranía de la Macarena

Swirling along a 62-mile route through Colombia, the Cano Cristales river is an example of nature's secretive artistry; for most of the year, it looks like a regular, clear river. However, between June and November, the normally clear waters reveal a hidden world of vibrantly colored flora. The red pigment is from Macarenia clavigera, an aquatic plant. Which is a plant endemic to Colombia. Clingy and fast-growing, the plant thrives fastest in the river's roaring spots. The plant's colors transform as it moves through various stages of life: green when youthful, then yellow, pink, and finally maturing into a stunning vivid red.

The river’s unusual spectacle

The river's deep red hue only emerges after the river drops to a specific level, allowing sunlight to reach and nurture the plants but not so low as to dry them. The result? A breathtaking spectacle that unfolds for only a few weeks each year. This brief window provides a glimpse of the unique plant life, and makes Cano Cristales a destination for nature enthusiasts visiting Colombia. The river's peculiar color inspires a variety of scientific and spiritual interpretations.

Macarenia Clavigera — The Master of Color

Understanding Macarenia clavigera, the rare aquatic plant providing the river's vivid splash, is a story worth telling. This plant is a chameleon, changing colors throughout its life cycle. The plant thrives on the walls of the river’s most turbulent parts. That makes its transformation all the more unusual. Locals call it the "liquid rainbow." It turns the water a vibrant red. Unlike the polluted, tinted waterways elsewhere, this South American river actually has clear water.

The Life of Macarenia Clavigera

Macarenia clavigera plants have a four-step life cycle. Its colors change from green to red, as the plant ages. Starting its life as a young green shoot, it turns yellow, blossoming into pink and then entering its final stage of life with a brilliant red hue. This transformation is why the river turns red. The species is most vulnerable during the pink-stages, prone to damage from water currents.

The Timing of the Red Tide

The Cano Cristales river appears red for a brief period. The river drops enough to permit sunlight to reach the bed beneath, yet not so low that it dries the plants. If the timing is off by a few weeks, the plant life recedes. The river returns to its ordinary hue, a clear stream running silently over plain stones. This phenomenon occurs between June and November. Between these months, visitors can witness one of the most incredible sights in nature.

Visitors to the Crimson Wonder

For decades, tourists have been drawn to the river. For many, it’s a mystical experience. It looks like a deep, blood-red river. The clear waters reveal plant life on the riverbed. It's the only effect of its kind in the world.

The Water’s Colorful Contradiction

Water in the river at all times is clear, the pigment is on the riverbed. This makes the Cano Cristales waters an interesting contradiction. Visitors can scoop the water into their hands and see that it's colorless. The red comes from the vibrant Macarenia clavigera plant.

The Macarenia Clavigera

The same riverbed that normally contains clear water nurtures the aquatic plants. They turn the river into a nature-created painting. When the river flow is just right, it’s as if it amplifies the colors on the bed beneath. The riverbed paints an underwater picture, and sunlight is the artist's brush.

Visit the Liquid Rainbow

The Cano Cristales river offers a brief, and memorable, look. It's a unique place to visit for nature enthusiasts. Sometimes, the best ways to experience natural phenomena are to visit places like these. Locals continue to share stories about the “liquid rainbow."