Why do giant stem-rosette plants grow on high tropical mountains?

Giant stem-rosette plants thrive on high tropical mountains primarily as an adaptation to the harsh, freezing conditions of their environment. These plants, which can reach heights of three metres or more, possess persistent dead leaf bases that act as insulation for the water-containing tissues within their stems.1

This protective mechanism is crucial because these plants inhabit high-altitude environments—up to 4,300 metres—where temperatures can drop to freezing levels almost every night. The development of this shared characteristic among unrelated species across different continents, such as Espeletia and Puya in the Andes and Dendrosenecio and Lobelia in East Africa, serves as a classic example of convergent evolution, where distinct organisms evolve similar traits in response to identical environmental pressures.1