It is said that to climb up Kilimanjaro is to walk through four seasons in four days. It is true, of course, and nowhere is this phenomenon more apparent than in its flora. The variety of flora found on Kilimanjaro can be ascribed in part to the mountain’s tremendous height and in part to its proximity to both the equator and the Indian Ocean. Add to this the variations in climate, solar radiation and temperature from the top of the mountain to the bottom and you end up with the ideal conditions for highly differentiated and distinctive vegetation zones.
Cultivated zone and forest (800m-2800m)
The forest zone, along with the cultivated zone that lies below it, together receive the most rainfall – about 2300mm per year – of any part of the mountain. The forest zone also houses the greatest variety of both fauna and flora.
The star of the montane forest zone is the beautiful flower Impatiens kilimanjari, an endemic fleck of dazzling red and yellow in the shape of an inch-long tuba. You’ll see them by the side of the path on the southern side of the mountain. Vying for the prime piece of real estate that exists between the roots of the trees are other, equally elegant flowers including the beautiful violet Viola eminii and Impatiens pseudoviola.
Heath and moorland (2800m-4000m)
These two zones overlap, and together occupy the area immediately above the forest from around 2800m to 4000m – known as the low alpine zone. Temperatures can drop below 0°C up here and most of the precipitation that does fall here comes from the mist that is an almost permanent fixture at this height.
Immediately above the forest zone is the alpine heath. Rainfall here is around 1300mm per year. Grasses now dominate the mountain slopes, too, picked out here and there with some splendid wild flowers including the yellow-flowered Protea kilimandscharica. Another favourite, and one most readers will recognise instantly, is the back-garden favourite Kniphofia thomsonii, better known to most as the red-hot poker (pictured right).
Climbing ever further, you’ll soon reach the imperceptible boundary of the moorland zone, which tends to have clearer skies but an even cooler climate. Average per annum precipitation is now down to 525mm. The most distinctive plant in this area – indeed, on the entire mountain – is the senecio, or giant or tree groundsel (below right). Groundsels tend to favour the damper, more sheltered parts of the mountain, which is why you’ll see them in abundance near the Barranco Campsite as well as other, smaller valleys and ravines.
Sharing roughly the same kind of environment is the strange lobelia deckenii (left), another endemic species and one that bears no resemblance to the lobelias that you’ll find in your back garden.
Alpine desert (4000m-5000m)
By the time you reach the Saddle, only three species of tussock grass and a few everlastings can withstand the extreme conditions. This is the alpine desert, where plants have to survive in drought conditions (precipitation here is less than 200mm per year), and put up with both inordinate cold and intense sun, usually in the same day. Up to about 4700m you’ll also find the Asteraceae, a bright yellow daisy-like flower and the most cheerful-looking organism at this height.
Ice cap (5000m-5895m)
On Kibo, almost nothing lives. There is virtually no water. On the rare occasions that precipitation occurs, most of the moisture instantly disappears into the porous rock or is locked away in the glaciers.
That said, specimens of Helichrysum newii – an everlasting that truly deserves that name – have been found near a fumarole in the Reusch Crater, a good 5760m above sea level, and lichen is said to exist right up to the summit. While these lichens may not be the most spectacular of plants, it may interest you to know that their growth rate on the upper reaches of Kilimanjaro is estimated to be just 0.5mm in diameter per year; for this reason, scientists have concluded that the larger lichens on Kilimanjaro could be amongst the oldest living things on earth, being hundreds and possibly thousands of years old!