The 150-year-old mystery concerning the origins of the rare, all-white trees that dot redwood forests in California may have finally been solved, The Mercury News reports. Albino redwoods, genetically mutant trees that lack the chlorophyll that turns most leaves green, are parasitic and only grow at the base of California (or coast) redwoods, Sequoia sempervirens. But according to new research being presented at this week’s Coast Redwood Science Symposium in Eureka, California, they may be doing more than just mooching by serving as filters for toxins in the soil around them.

Scientists first discovered the odd trees in 1866, though they are mentioned in Native American legends and were reportedly used as part of traditional cleansing ceremonies long before that. Because they lack chlorophyll, they can’t complete the photosynthesis process necessary for plants’ survival, and so they latch onto other trees, taking nutrients straight from the roots of the parent tree.

They typically only grow to be about 10 feet tall, compared to the staggering heights of California redwoods, a species that includes the tallest tree in the world—the 380-foot Hyperion in Redwood National Park.

Cole Shatto via Wikimedia Commons // CC BY-SA 3.0

However, according to research by UC Davis Ph.D student Zane Moore, who has been studying albino redwoods since his undergraduate days at Colorado State University, the white plants are more than just nutrient-sucking parasites. They may be helping filter pollution. His analysis found that the leaves of albino redwoods contain high levels of heavy metals like copper, nickel, and cadmium—more than double what was found in green leaves. They might act like a liver for their parent plants, filtering out toxic materials from the soil.

The hypothesis will need to be tested further, but it’s a promising prospect, especially since, if true, it could mean that the rare trees could be planted elsewhere to help clean up environmental pollution.

[h/t The Mercury News]

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