Above. Kilimanjaro's glaciers. The Furtwangler Glacier (ca 5750 m) in the centre and thelarge Northern Icefield can be seen on the horizon.Facing page. Fire and ice. Sunset on Kibo, Mount Kilimanjaro. Photos: C.K. Willis.

The ultimate challenge for anyclimber in Africa must surelybe to reach the summit of the

highest mountain in Africa, and oneof the world's highest free standingmountains, Mount Kilimanjaro(affectionately known as 'Kili').Situated three degrees and some330 km south of the equator innorthern Tanzania, MountKilimanjaro, with it's highest point,Uhuru Peak, measured at 5895 m(19 340 ft) above sea level, holds aunique place in both the Westernand African psyche. The mountainhas featured in stories, films andeven popular songs, including'Africa' by the group Toto, and'Kilimanjaro' by Juluka. I had theopportunity, in February this year,to climb Africa's highest mountain ­via the less popular, albeit morescenic, Machame Route (also knownas the 'Whiskey' Route, as opposedto the more popular Marangu or'Coca-Cola' Route), a total distanceof about 80 km, with an altitudinalrange of about 9500 m. To put theheight of the mountain intoperspective, southern Africa'shighest point, Lesotho's, ThabanaNtlenyana, is a mere 3482 m.Walking seven to eight hours perday, single file on a well-worn pathas part of a group of eleven climbersdoes not allow much spare time forbotanizing. On days four and five,we reached the summit ofKilimanjaro and descended thesame day, walking for twenty-threehours, with two hours sleep andcovering an altitudinal range of4740 m (from Barranco Camp at3950 m via Barafu (4600 m) to thesummit at 5895 m and back down toMweka Camp at 3100 m)!

Despite its popularity(18 000 visitors each year which ismore than 300 per week), very littlepopular literature is available on theflora of Mount Kilimanjaro andinformation remains scattered ininaccessible scientific journals orregional field guides. It is hopedthat this account of the flora ofKili,manjaro will serve as usefulbackground information for anyoneinterested in plants and attemptingKilimanjaro in the future.

Kilimanjaro National Park and the'Three Peaks'A large })Qrtion of the mountain, the756 km area above the 2700 mcontour, is conserved within theKilimanjaro National Park, managedby Tanzania National Parks. Thepark was established in 1973 andofficially opened in 1977. It has six

Veld &' Flora December 2000

corridors or rights of way throughthe Kilimanjaro Forest Reservewhich was established in 1921. Inrecognition of its beauty, culturaland spiritual significance and size,Mount Kilimanjaro was declared aWorld Heritage Site in 1989. MountKilimanjaro is composed of threeextinct volcanoes: Kibo (consideredby some to be dormant, rather thanextinct) at 5895 m in the centre,Mawenzi at 5149 m (16 893 ft) inthe eaft; and Shira at 3962 m(13 000 ft) in the west. The threepeaks repr~s'ent three g~nerations ofvolcanic activity, Shira the oldest(and most eroded), and Kibo theyoungest. Whereas the older twohave been largely destroyed byerosi.on, Kibo is a perfectly shapedcone with a caldera, about 2 kmwide, in the centre of which is asmall secondary eruption cone withits own crater. The majesticmountain, which ceased growing450 000 years ago, rises 4800 mabove the surrounding plains whichaverage around 1000 m above sealevel. The longest axes of MountKilimanjaro, running north-east tosouth-west, are about 60 km longand 40 km across.

ClimateMount Kilimanjaro is regarded asthe driest of the tall East Africanmountains. Unlike Mount Kenyaand the Ruwenzoris, both of whichhave several small lakes or tarns,Kilimanjaro has only one permanenttarn, located close to Mawenzi.Rainfall varies both with aspect andaltitude. Most rain falls betweenMarch and June, and it is duringthis period that rains fall at the base

of the mountain, and snow falls atthe top of the mountain. The shorterrainy period is from October toDecember. January and February areusually dry, warm and clear withbrief rainshowers which make goodclimbing conditions.

Ninety six percent of the wateron Kilimanjaro originates in theforest zone, where it percolatesthrough the soil to emerge assprings lower down the mountain.Kilimanjaro's forests receive about2000 mm rainfall per annum on thesouthern slopes, with the same

. forests receiving about 1000 mm on .the northern and western slopes.Above 1500 m the rainfall decreaseswith altitude so that the alpine zonereceives between 250 and 125 mm,resulting in an alpine desert in theupper reaches of the mountain.At the summit, most of theprecipitation falls as snow, ratherthan as rain.

Botanical explorationSeveral plant collections weremade on Mount Kilimanjarobetween 1861 and the early 1900s,the most notable being those ofVon der Decken, Johnston, Meyerand Volkens. Many of the plantscollected during the late 1800s onthe mountain were described inEurope by Engler, and named afterthe individuals who collectedthem. * Many plants, as could beexpected, have the species name'kilimandscharica' or 'kilimanjari',

Kilimanjaro's vegetationMount Kilimanjaro has a rich anddiverse flora which includes over1800 species of flowering plants

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Above. The endemic ImpatienskiJjmanjari subsp. kiJjmanjari(Balsaminaceae) growing in the montaneforest belt on the southern slopes ofKilimanjaro.

Below. Carduus keniensis, a member ofthe Asteraceae family, growing in theericaceous belt on Kilimanjaro. Thisspecies belongs to the same genus as thecommon European thistles.

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within 163 families and 760 genera,and an unusually high speciesdiversity among lower plants ofapproximately 720 species ofbryophytes (596 known species)and lichens (120 species).

Five vegetation belts can berecognized. Olov Hedberg, therenowned Swedish botanist whodescribed the vegetation belts of theEast African mountains in 1951,defined a vegetation belt as an'altitudinal region' which can betraced on all (or most) mountains ofsufficient height in a definite partof the world, as for instance themontane forest belt on the EastAfrican mountains. AlthoughHedberg only recognized threevegetation belts on Kilimanjaro(montane forest, ericaceous belt andthe alpine belt), Mwasaga in 1991included two additional vegetationbelts, namely the woodland andbushland belt, and the cultivatedbelt.

The upper limit of the woodlandand bushland belt ranges between900 m (southern slopes) and 1500 m(northern slopes). It is characterizedby a mosaic of Acacia bushland andCombretumlTerminalia woodland.The cultivated belt more or lessencircles the mountain and reachesits highest point on the southernslope (1900 m), but in most areasextends no higher than 1700 m.Crops cultivated il;l this zone .include coffee, bananas, maize,

'rbeans, millet, potatoes, cabbage,carrots, beets, onions and tomatoes.

The lower boundary of themontane forest belt is approxi­mately 1700 m on the southern sideand 2200 m on the northern side.The upper boundary reaches nearly3000 m along the southern side and2800 m on the western and northernsides. Trees characteristic of thisbelt include Xymalos monospora,Tabernaemontana ventricosa,Macaranga capensis var. kilimand­scharica, Myrica saJicifolia,Maytenus undata, Prunus afdcana,East African pencil cedar Juniperusprocera and the East Africanredwood Hagenia abyssinica. Othertree species, several of which arealso known from southern Africa,include Ilex mitis, Podocarpusmilanjianus, Ocatea usambarensis,Olea africana , Nuxia congesta,Agauria salicifolia, the CapeChestnut Calodendrum capense andHypericum revolutum. The montaneforest belt receives about 2000 mmof rainfall per annum on thesouthern slopes, and containsseveral endemic plants. One species

which was flowering prolificallyduring our visit was Impatienskilimanjari subsp. kilimanjari withits brilliant red and yellow flowersshining in the forest undergrowth.An endemic 1. kilimanjari subsp.pocsii was described by ChristopherGrey-Wilson from the uppermontane forest on the northern sideof Mt Kilimanjaro as recently as1997. The pink-flowered Impatienspseudoviola may also be seen here.Other shrubs and herbs includeMimulopsis kilimandscharica andSolanecio mannii. The forest zoneincludes many lichens (Usnea),mosses and ferns like Aspleniumactiniopteroides, A. volkensii andtree ferns, Cyathea (see photo onp. 166). A unique community ofbryophytes is known to develop onthe stems of the tree fern Cyatheamanniana. The giant Lobeliagiberroa grows as scatteredindividuals along streams and moistdepressions in the montane forestzone from 1550 m to 3000 m.

Bernard Verdcourt of the Royal BotanicGardens, Kew, apparently first came acrossHelichrysum meyeri-johannis on reachingthe top of Mount Kilimanjaro in the early1970s. The story goes that the porters'presented members of his team with brightgarlands made from the capitula of thisplant woven into a wreath of stems from aspecies of Lycopodium'. Verdcourt's'wreath' can still be found amongst thecollections in the Sir Joseph Banks Museumfor Economic Botany at Kew. This species,named after Hans Meyer, is common indamp to dryish alpine grassland between2600 and 4250 m. Flowering at almost anytime of the year, it has also been recordedon Mount Elgon, Cherangani Hills andMount Kenya. Drawing by Helen Haywood

(from Curtis's Botanical Magazine 12(1), February 1995).

Veld &- Flora December 2000

Above. One of the few flowering plants observed above 4600 m. This member of theAsteraceae was observed flowering at ca 4800 m, between Barafu Camp and Stella Pointon Kibo.Below. A stark section of the alpine belt on Kilimanjaro. Photos: C.K. Willis.

The forest zone on Kilimanjaro isless differentiated than on otherEast African mountains andcontains neither a bamboo(Arundinaria alpina) nor Hagenia­Hypericum zone. On most otherEast African mountains, such asMount Kenya (see Burrows &Burrows in Veld Er Flora 80(2),1994), Mt Elgon and Mt Ruwenzori,there is a bamboo forest zonebetween 2200 and 3200 m. OnKilimanjaro a few very smallpatches are reported to exist only onthe northern and north-westernslopes. It has been estimated that69% of the flowering plant speciesfound above the cultivated zone onMount Kilimanjaro are restricted tothe montane forest. This figure iseven higher for the bird (78%) andlarger mammal species (80%).

The ericaceous belt extends fromthe upper limit of the forest zone, atabout 3000 m, to an elevation of-¥lllfSlximate.1v MlfULm. IhB.e.rir.a­ceous belt of Kilimanjaro containstwo zones, the moorland zone andthe ericaceous-shrub zone. Themoorland zone (between 2800 and3250 - 3400 m) consists of tussockgrassland with scattered low trees orshrubs of Erica excelsa and Ericaarborea, together with Artemisiaafra, Stoebe kilimandscharica,Helichrysum newii, Helichrysummeyeri-johannis (see accompanyingpainting) and the conspicuous spinyrosette plant Carduus keniensis alsofound on Mount Elgon, theAberdares and Mount Kenya.

The dominant shrubs of theericaceous-shrub zone are the samespecies as found in the moorlandzone, intermingled with Prateacaffra subsp. kilimandscharica (thecommonest Protea species on themountain), Adenocarpus mannii,Anthospermum usambarense and,in boggy areas and along streams,the sedge Carex monostachya(Cyperaceae), Senecio johnstoniisubsp. johnstonii var. cottonii andS. johnstonii subsp. johnstonii var.kilimanjari. This zone extends fromthe upper limit of the moorlandzone at about 3250 m up to 3900 mor 4000 m. It is generally acceptedthat the present appearance of theericaceous belt has largely beenattributed to fire, caused by man. Asa result of frequent fires along theupper regions of the montane forest,the ericaceous belt has replaced themontane forest in many areas.

The alpine belt extends from thetop of the ericaceous belt at about4100 m to the upper altitudinallimit of plant growth. The highest

Veld Er Flora December 2000

recorded flowering plant onKilimanjaro has been Helichrysumnewii at 5670 m in Kibo's crater,demonstrating an ability to survivein highly adverse environments.Only about fifty-five species ofhigher plants have been recordedabove 4000 m on Kilimanjaro,compared with many hundreds inthe lower zones. Important generainclude Senecio, Lobelia, the sclero­phyllous shrubs Aichemilla and theeverlastings Helichrysum,acaulescent (absence of an above­ground stem) rosette plants of thegenera Haplocarpha, Haplos­ciadium and Dianthoseris, as wellas grass tussocks of the generaFestuca, Agrastis, Koeleria andPentaschistis. In its lowest part upto about 4300 m, a Helichrysumcommunity dominates, composedmainly of Helichrysum newii andother Helichrysum species. Anotherimportant shrub of this belt is theyellow-flowered EUJ.yqDs dacz;v­dioides. This belt is also home to

Kilimanjaro's giant senecios andlobelias.

An interesting process isassociated with the alpine belt.As a result of the nightly freezingand the daily thawing of the upperlayer of the soil, ice crystals thatform in the soil at night loosen andmove the topsoil of the alpine semi­desert and desert. This form of'solifluction' can be tolerated onlyby organisms that lie loosely on theground and that can easily changetheir position. Some mosses(Grimmia) change their positiondaily as the soil surface moves, andas a result, ball-shaped coloniesdevelop with shoot apices in alldirections. Such 'moss balls' havebeen described in other arctic anddesert areas of the world.

Mosses, liverworts and fernsOf the 596 known bryophytespecies, 415 are mosses and 1811ipecies are liverworts. Twelvespecies of bryophytes are strict

endemics to Mount Kilimanjaro andrepresent 2% of the total bryoflora.In terms of Afroalpine endemics,though, there are eighty-threespecies of Afroalpine endemicmosses and twenty species ofAfroalpine endemic liverworts.The lower plants serve an importantfunction in terms of regulating thewater flow and reducing the loss ofwater through evaporation onMount Kilimanjaro. Work on theferns of Mount Kilimanjaro hasrevealed that there are over 130species of ferns and fern allies onthe mountain, with the highestrichness recorded in the montaneforest belt on the southern slopes,especially between 2000 and2300 m. The abundance of fernsdecreases abruptly above 2900 mand below 1100 m. The highest fernon Kilimanjaro is CystopterisjragiJis (recorded by Hedberg at4750 m), the highest pteridophyte ofAfrica and probably the hardiest ofalpine ferns.

Africa's giantsThe plants for which Kilimanjaro ismost famous are the giant seneciosor groundsels (previously classifiedin the genus Dendrosenecio),Senecio johnstonii subsp. johnstoniivar. johnstonii, Senecio johnstoniisubsp. johnstonii var. cottonii andS. johnstonii subsp. johnstonii var.kilimanjari, and the giant lobelias,Lobelia giberroa, 1. deckenii subsp.deckenii (see cover) and 1. deckeniisubsp. incipiens. As a rule the giantsenecios and giant lobelias grow inmoist, open sites and possess anapical rosette of leaves.

Lobelia giberroa is certainly themost Widespread of the giants,occurring from northern Ethiopia tothe Viphya Mountains in northernMalawi. It generally grows in

montane forests as scatteredindividuals between 1550 and3000 m. The rhizomatous1. deckenii subsp. deckenii occupiesmoist sites in the ericaceous andalpine zones (3000-4000 m) whilst1. deckenii subsp. incipiens growsin the upper montane forest zone(2700-3150 m). Senecio johnstoniisubsp. johnstonii var. johnstoniigrows in the upper portion of themontane forest zone as a many­branched tree up to 8-10 m tall, andsmaller individuals are found in thelower part of the ericaceous belt(2500-3100 m). The other twovarieties of giant Senecio tend tohave thicker stems, fewer branches,and persistent dead leaves(marcescent leaves) surround thethicker stems or branches.S. johnstonii subsp. johnstonii var.kilimanjari spans the ericaceous belt(3000-3800 m), whereas Seneciojohnstonii subsp. johnstonii var.cottonii grows in the alpine zone(3700-4500 m). The mostspectacular and largest populationof giant groundsels I observed onthe Machame Route was in theBarranco Valley, where Seneciojohnstonii subsp. johnstonii var.cottonii grew alongside 1. deckeniisubsp. deckenii. Research on thegiant groundsels has revealed thatthe average annual stem elongationrate is about 2.5 em. Specimens canattain height~ of 10 m: the tallestspecimens are abcfut 250 years' old.(The weakly expressedseasons in the tropicalalpine zone mean thatannual rings or otherrhythmical anatomicalfeatures ca~not beused for age determi­nation in theseplants.) Tamas P6cs,a researcher on the

bryophyte flora of MountKilimanjaro, has observed aboutforty epiphytic species on the giantSenecio trunks. Chloroplast DNA sofar examined suggests that the giantsenecios at high altitude originatedon Mt Kilimanjaro, with subsequentdispersion to the adjacent Mt Meru,north to the Kenyan mountains(Aberdares, Mt Kenya, CheranganiHills and Mt Elgon), west to theRuwenzori Mountains, and thensouth to the Virunga Mountains andMount Kahuzi. This dispersion andsubsequent speciation all occurredin the past million years.

Convergent evolution hasresulted in similar giant stem rosetteplants evolving independently inthe richest high-mountain flora ofthe world, the 'paramo' vegetation,which is restricted to the northernAndes of South America andadjacent southern Central America.Members of the genus Espeletia(Asteraceae), the jrailej6n (literally,'big friar' - so called because of thegreyish woolly coat of pubescence)are the classical example, verysimilar to the giant groundsels ofeastern equatorial Africa.

Vegetation classificationMuch has been written about thezonation of the vegetation onAfrica's tropical mountains, as wellas the links between the 'Cape'Flora, the Afromontane Region andthe flora associateq. with the

Above. Giant senecios or groundsels,Senecio johnstonii subsp. johnstonii var.cottonii on Kilimanjaro, likened by OttoKersten to 'dancing spectres'. Taken froma translation of Otto Kersten's account ofhis journey up Kilimanjaro with Baronvon der Decken in 1862. (Originallypublished in German in the 1870s. Thetranslation was published in 1965 inTanganyika Notes and Records 64.)Left A grove of tree ferns in the montaneforest belt on the Mweke Route, southernslopes. Photo: C.K. Willis.

Veld &- Flora December 2000

The giant senecio or groundsel, Senecio johnstonii subsp. johnstonii var. cottonii in the Barranco Valley, Kilimanjaro, at an altitude ofabout 3900 m. Photo: C.K. Willis.

Afroalpine or Alpine belt. The useof different terminologies by a rangeof scientists can easily be confusingto someone trying to make sense ofthe various floras and publicationsconcerning Africa's temperate flora.Considering the similarities anddifferences between the variousmontane floras in sub-SaharanAfrica, Prof. Peter Linder in 1990indicated that 'The temperate floraof Africa shows a degree ofhomogeneity across its distributionrange that suggests that its recog­nition as an "Afrotemperate Region"might be profitable. Thishomogeneity is reflected ecologi­cally by similar vegetation structuralchanges in response to disturbance,and phytogeographically by a suiteof genera of shrubby and herbaceousplants and species of trees that arecommon to all the Afromontaneareas.' He went on to suggest thatwithin this so-called 'AfrotemperateRegion', various centres ofendemism, such as the CapeFloristic Region, the AfromontaneCentre and the Drakensberg andsurrounding mountains, could berecognized. Much research stillneeds to be done to understandmany aspects of Africa's temperateflora, but at least Linder's suggestionhas the benefit of placing Africa'stemperate vegetation into thecontext of a pan-African classifi­cation, as opposed to consideringeach area as a separate unit which isclassified individually and not in

Veld & Flora December 2000

relation to temperate vegetation inother areas of the African continent.

Mount Kilimanjaro, like all highmountains around the world, hasmany moods, and although it mightnot be the most diverse of Africa'shigh mountains in terms of plantdiversity, it does neverthelessdis~lay very clearly the distinctivezonation'of vegetation so typical ofAfrica's high mountains. It iscertainly a must for anyone with aninterest in phytogeography andmountains, particularly from anAfrican perspective. Of course youcail also climb it 'because it isthere'.®

AcknowledgementsSpecial thanks to Steven Giddings,Ela Romanowska, Dawid Malan and therest of the group we climbed with, for theircompanionship and support both prior to,and during our ascent of MountKilimanjaro. The assistance andprofessionalism of our guides (Elias andHumphrey) and porters is also gratefullyappreciated.

Further readingAllan, 1. ed. 1991. Guide to Mount Kenya

and Kilimanjaro. The Mountain Club ofKenya, Nairobi.

Blundell, M. 1987. Collins photo guide tothe wild flowers of East Africa.Harper Collins, Hong Kong.

Burns, C.M. 1998. Kilimanjaro & MountKenya: a climbing and trekking guide.The Mountaineers, Seattle.

Hanby, J. 1992. Kilimanjaro National Park.Tanzania National Parks/African WildlifeFoundation, Arusha.

Newmark, W.D. ed. 1991. The Conser­vation of Mount Kilimanjaro. IUCN,

Gland, Switzerland and Cambridge.Reader, J. 1982. Kilimanjaro. Elm Tree,

London.

*A list of early Kilimanjaro plant huntersand some of the plant taxa commemoratingthem is available on request from thePublications Manager at the BotanicalSociety, Private Bag X10, Claremont, 7735.Tel (021) 797 2090, fax (021) 7972376,e-mail <botsocsa@gem.co.za>.

About the authorChristopher Willis is a graduate of theUniversity of Cape Town and University ofPretoria. He spent six years lecturing inphytogeography and plant conservation atthe University of Venda before taking upthe post of Regional Coordinator of theSouthern African Botanical DiversityNetwork (SABONET) Project in theNational Botanical Institute (NBIl. Pretoria,in 1996. He was appointed to the positionof Director: Gardens and HorticulturalServices within the NBI in August 2000.

Christopher Willis next to a giant lobeliabetween Machame and Shira Camps,Kilimanjaro (at about 3500 m).Photo: E. Romanowska.

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