The Rwenzori, like other tropical mountains, have a range of exotic vegetation organized in discrete vegetation belts distributed across the altitudinal gradient. The montane forest zone extends from about 1,800 to (2,200) 2,400 m, and varies from dense forest (mainly confined to valley bottoms and ridge tops), through bracken or shrub dominated areas with scattered trees, to grassy glades. Common trees include Albizia spp., Dombeya spp., Olea spp., Podocarpus milanjianus, Prunus africana and Symphoniaglobulifera. The bamboo zone, which is dominated by Sinarundinaria alpina, reaches its upper limit at about 2,600 (2,800) m on the west and 3,000 m on the east side. The Ericaceous zone (Fig. 2a), extending from the end of the bamboo up to (3,800) 3,900 m, is characterised by broad-leaved trees (Hypericum spp. or St. John’s Wort, Hagenia abyssinica and Rapanea rhododendroides), arborescent heathers (Erica spp.) draped with Usnea spp. (Old Man’s beard, a lichen), flowering shrubs (typically Helichrysum guilelmii), scattered tree groundsel (mostly Senecio longeligulatus), and giant lobelias (chiefly Lobelia stuhlmannii). The dominant mosses are Breutelia stuhlmannii and Sphagnum spp.
Common plants in the Alpine zone include Carex runssoroensis tussocks, as well as Helichrysum stuhlmannii (everlasting flower) and Alchemilla spp. (Ladies Mantle). Most celebrated in this zone are the so-called ‘giant rosette’ plants of the genera Senecio and Lobelia (primarily S. adnivalis, S. friesiorum and L. wollastonii), which are well-developed in ravines and other sheltered or well-watered sites. Almost all rock surfaces in the Nival zone, if not overlain by glaciers, are covered by lichens of the genera Umbilicaria and Usnea and mosses, such as Rhacocarpus humboldtii forming bright orange carpets.
Rwenzori is exceptionally rich in endemics: it harbours at least 1 hawkmoth, 6 butterflies, 19 bird species and 12 small mammals that occur only here and/or in a few other highlands on either side of the Albertine Rift (including the Rwenzori hyrax Dendrohyrax arboreus ruwenzorii and Rwenzori Leopard Panthera pradus ruwenzori). Twelve species are on the IUCN Red List of Threatened Animals including the ‘vulnerable’ Moon striped Mouse (Hybomys lunaris), the ‘vulnerable’ Rwenzori Horse-shoe Bat (Rhinolophus ruwenzori), the ‘near threatened’ Rwenzori Otter Shrew (Micropotomogale ruwenzori) and the ‘least concern’ Rwenzori Turaco (Ruwenzorornis johnstoni)
The park is home to 70 species of mammal, including six Albertine Rift endemics; 12 are endemic to the park and three are rare species. Other mammals include the elephant, chimpanzee, Rwenzori otter and leopard. Though wildlife is difficult to spot in the dense forest, do look out for primates such as colobus (Angola and black-and-white varieties are both present) and blue monkeys; small antelope such as bushbucks; and unusual reptiles such as the three-horned chameleon.