And another entry today from UBC Botanical Garden’s Eric La Fountaine, responsible for both the photograph and the write-up. Eric writes:
Spontaneous plant combustion? The photograph shows the charred remains of a large colony of puya, either Puya chilensis or Puya berteroniana. Both are Chilean endemics. Local botanists who I toured with said that this sight can be witnessed occasionally in the wild. The curiosity is that only the puya are burned–no sign of fire damage occurs around the colony. When the phenomenon is observed, it appears to only occur in mature colonies. Some theorize that a type of spontaneous combustion involving chemicals in the mature plants, possibly ignited by the intense sun, is involved. Close inspection of the material revealed a delicate charcoal, like something that had smoldered without flame. Unfortunately, I can not find any substantiation or even discussion of this phenomenon.
Puya are known for their unearthly coloured flowers. These two Chilean species, locally known as chagual, are fairly common in central Chile. They are uncommon in cultivation, but can be grown in other areas, Puya berteroniana being the better candidate in temperate areas as it is more cold tolerant. ChileBosque has nice photos of both Puya chilensis and Puya berteroniana.