They are called sarcocaulescent trees — from sarco meaning “fleshy” and caulescent meaning “having a stem.” Each tree can store hundreds to thousands of gallons of water in their thick branches and trunks.
This superpower lets them survive in some of the driest places on Earth, like the Arabian Peninsula and the deserts of South America. Rain in these regions is rare and unpredictable, so they must absorb water quickly and hang onto it for a long time.
One striking example is the Boojum tree, a plant that looks — and sounds — like it came out of a Dr. Seuss book. It can grow more than 50 feet tall, with hundreds of skinny twigs sticking out from the stem, each covered in tiny leaves.
Another is the Elephant Tree, named for its stout trunk and crooked branches that look like, well, an elephant’s trunk.
One adaptation to drought is their waxy bark, which reflects sunlight. And many drop their leaves during dry periods to reduce water loss.
But the most remarkable feature is their green, photosynthetic stems, which let them make energy without leaves.
Because of these adaptations, sarcocaulescent trees offer shade and shelter for wildlife in the driest of habitats. And they spark intriguing questions for botanists — and all of us — to contemplate.
