Giant lobelia
The giant lobelia (Lobelia rhyncopetalum) is an endemic giant rosette plant that may reach up to 10 metres (with their inflorescence). The giant lobelia is the tallest plant growing in this harsh tropical alpine environment and its sheer size makes it a conspicuous feature on the treeless Afroalpine plateau in the Bale Mountains. The microclimate and the alpine adaptations of the giant lobelia were investigated in the Bale and Simien Mountains (Fetene et al. 1998). The microclimate and growth rate of different height classes was investigated with respect to temperature, relative humidity, and wind. It was concluded that large temperature fluctuations in the alpine environment are particularly extreme at or near the ground. Thus, by growing a large stem the giant lobelia protects its leaves and flowers from the harsher temperatures at lower heights, while accumulating heat from direct insolation. Young plants formed ‘night buds’ as insulation against night time freezing. In addition, giant lobelia roots reach down more than 1 metre into the soil in order to access sufficient water, which can be scarce on the soil surface in the dry season.