#yareta

Yareta or llareta is a velvety, chartreuse cushion plant in the family Apiaceae which is native to South America. It grows in the Puna grasslands of the Andes in Peru, Bolivia, northern Chile and western Argentina at altitudes between 3,200 and 5,250 metres.

Staying Alive in the Atacama

The Llareta (or yareta) plant (Azorella Compacta) of the Atacama Desert is well known for being one of the longest living organisms on the planet. Some of the larger specimens have been calculated to be approximately 3000 years old. While this is, by itself, a magnificent feat, the llareta holds some of it's most wonderful characteristics close. Literally.

Botanically speaking, these plants are masters at taking advantage of their desert environments, flaunting adaptations on par with the cactus'. As it's scientific name might suggest, llareta is composed of stems, often very long in older plants, that support a rosette of leaves that are tightly packed together. This type of compact growth is a valuable adaptation in a desert climate as it reduces the surface area to volume ratio – a smart move when you are trying to reduce evaporation.

When smaller stems are blocked from the sun, they die back, creating packing material that makes the interior of llareta very dense. It's so dense, in fact, that they can bear the full weight of a person seemingly without harm. But the dense core of these cushions provide a very helpful service for the plant. Not only is it a perfect sponge for holding water during times of drought, it is also a great way to keep the interior of the plant cool during the hottest parts of the day.

The plant's habitat preferences also help to reduce water loss. New plants often take advantage of small cracks in the rock surfaces in the desert (as shown in the picture below). These cracks provide perfect microclimates that offer cooler temperatures in hot weather, warmer temperatures in cold weather, more water during drought, and shelter from the winds that can blast through the open spaces. It also appears that the fringes of established plants create new microclimates also suitable for new, baby llareta.

Llareta has also found a niche in another aspect of life in the Atacama; humans have been using the plant for centuries, up to the present. The dense core is perfect for fires and even creates a flammable resin that produces a slow, nearly smokeless fire. Because of these valuable traits, it was used in mining operations and to power trains. However, the desirability of the plant has also caused its decline, and llareta is now an endangered species. This is particularly troubling because llareta also has some promising medicinal properties. Several studies, dating as far back as 1982 have shown that it is effective in treating diabetes caused by obesity.

Further Reading: Wickens, G. E. “Llareta (Azorella Compacta, Umbelliferae): A review”. Economic Botany. April-June 1995, Volume 49, Issue 2, pp 207-212 Photo Courtesy of Magnus von Koeller

Azorella compacta

3,000 year old Yareta plant