Yareta or llareta

The Yareta or llareta, bright green blobs that resemble moss-covered boulders, are actually flowering shrubs perfectly designed to withstand the high-altitude conditions of the Andes Mountains in Peru, Bolivia, northern Chile and western Argentina.

Wind, freezing temperatures and drought prove no match for Azorella compacta, a wild, inedible relative of parsley and fennel, which slowly and methodically ekes out an existence, growing as little as one meter a century.

Because of their slow growth rate, the largest shrubs are thought to be approximately 3,000 years old.

Given their density — a shrub can easily support the weight of a human — Yareta have been used like peat as a traditional fuel. Fortunately, South American governments have rallied to protect the endangered species.

Yareta is an evergreen perennial with a low, mat-like shape and hemispherical growth form that grows to around 6 m (20 ft) in diameter.[3] The self-fertile, pink or lavender flowers are hermaphroditic and are primarily pollinated by small flies, bees, wasps, and moths.[4]

The plant prefers sandy, well-drained soils. It can grow in nutritionally poor soils that are acidic, neutral or basic (alkaline) at altitudes of up to 5,200 metres (17,100 ft).[2] Yareta is well-adapted to high insolation rates typical of the Andes highlands and cannot grow in shade. The plant's leaves grow into an extremely compact, dense mat that reduces heat and water loss.[5] This mat grows near the ground where air temperature is one or two degrees Celsius higher than the mean air temperature. This temperature difference is a result of the longwave radiation re-radiated by the soil surface, which is usually dark gray to black in the Puna.[5]

Yareta is estimated to grow approximately 1.5 centimetres (0.59 in) per year. Many yaretas are estimated to be over 3,000 years old. These oldest ones have been reported to grow as slowly as 1⁄18 inch (1.4 millimeters) per year.[7] Its very slow growth makes the traditional practice of harvesting it for fuel highly unsustainable.

Jonathan, the most beloved resident of St. Helena, a tiny island in the South Atlantic, was born about 1832, five years before the coronation of Queen Victoria. Since then, the giant tortoise has lived through nearly 40 US presidents. Jonathan is an Aldabra giant tortoise (Aldabrachelys gigantea) thought to have hatched around 1832 in the Seychelles and brought to St. Helena in 1882 as a gift to the island’s governor, already fully grown. 

A new genetic analysis has revealed potential clues to the longevity secrets of a giant tortoise named Jonathan, the world’s oldest land animal. Researchers say the findings could eventually inform treatments aimed at slowing age-related cellular decline in humans.

Believed to be 194 years old, Jonathan is an Aldabra giant tortoise — a species native to the islands of Seychelles in the Indian Ocean — and he has spent most of his life on the remote South Atlantic island of St. Helena, a British Overseas Territory.

Giant tortoises are among the longest-lived land animals on Earth, with some records indicating they can regularly survive for more than a century. But Jonathan, approaching his 200th birthday, is an extreme example in this already special group.

One explanation for these animals’ extended lifespan might be that they take life very slowly — even at the genetic level, according to a new study published Wednesday in the journal Science Advances.

“The assumption has always been that their metabolic rate is very low compared to us,” said study coauthor Justin Gerlach, a fellow in biology at the University of Cambridge in the United Kingdom. “That means that the processes that are going on inside the cells are slower, so there are fewer chemical reactions and therefore less damage to the cells and to the DNA.”

Gerlach and his colleagues tested those assumptions by examining Jonathan’s genome — the complete DNA set — as well as his epigenome, the switches that turn genes on and off. The researchers found 287 gene variants associated with protecting the animal from the inevitable cellular damage that comes with time.

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“He does have some genes that are particularly good for DNA repair and reducing inflammation,” said Gerlach, referring to two key mechanisms that are known to slow down aging processes.

More specifically, the analysis suggests that Jonathan can continue expressing the right genes at the right levels even in old age. This process typically starts to break down much earlier in most other animals, including humans, Gerlach said.

He never met the other notable to live on the island, Napoleon, as the French emperor died in exile there in 1821. The gentle reptilian giant originated from the Seychelles in the Indian Ocean, but made the move to the Atlantic as a gift to a future governor of St. Helena in 1882. Since then he’s roamed about the governor’s grand island estate, where he enjoys the company of other giant tortoises and frequent human guests.