On Mount Kenya, Lobelia telekii occurs at elevations of . It inhabits the drier hill slopes, while its close relative Lobelia keniensis prefers the moister valley bottoms. Partially fertile hybrids do occur. The hill slopes often have rocky moraines that are home to Mount Kenya rock hyrax, which sometimes eat lobelia leaves and inflorescences, but herbivores are generally deterred by the lobelia's bitter toxic sap, which contains alkaloids, probably including lobeline.