Porous lavas result in most rain water rapidly vanishing underground only to reappear as springs on the lower slopes of mountain. As a result the flora, particularly at higher altitudes, is poorly developed or almost non-existant as is the case on the desert like Saddle. The lower southern slopes are well-forested with species such as Podocarpus milanjianus, Nuxia congesta, Ficus and Phoenix (wild date palms). The moorland starts abruptly at about 3100m, initially as thick stands of Giant Heathers Erica arborea higher thinning and giving way to Protea and Helichrysum bushes. From about 3500m to 4200m Lobelia and Senecio giant groundsels are often found in abundance. Noticeable is the lack of a a bamboo belt commonly encountered on many other East African mountains.