How is convergent evolution shown by giant plants in the Andes and East Africa?

Convergent evolution is demonstrated in the high-altitude tropical mountains of the Andes and East Africa through the independent development of giant stem rosette plants.1

In these harsh, high-altitude environments—which can experience freezing temperatures nearly every night—these unrelated plants have evolved similar physical characteristics to survive. These giant herbs, which can reach heights of three meters or more, possess persistent dead leaf bases that act as insulation, protecting the water-containing tissues of the stem from nightly frost.12

While these plants are not closely related, they occupy similar ecological niches on different continents:
* In the Andes: Examples include the Espeletia (often called frailejones) and Puya.134
* In East Africa: Examples include Dendrosenecio (tree groundsel) and Lobelia.15

The emergence of these identical adaptive traits in different species under the same environmental pressures across vast geographic distances is a classic example of convergent evolution.1