The Flora of the Falls
The vegetative flora of the Victoria Falls region is determined by two main factors - climate and soil type. The Zambezi river flows over solid basaltic rock, and basalt soils tend to be shallow and stony. However to either side of the Zambezi river basin are overlying reddish Kalahari sands, and which is often intermixed with the shallow basaltic soils.
The Kalahari sands support Miombo/Kalahari woodland, typical of the region, and which is dominated by several species: Zambezi Teak (Baikiaea plurijuga), various species of Brachystegia, museshe (Burkea Africana), mubako (Erythrophleum africanum) and muzauli (Guibourtia coleosperma).
The basaltic soils tend to support either mopane (Colophospermum mopane) dominated woodland or mixed mopane scrub. A good example of mopane woodland, protected from the attentions of elephant since the park was fenced in the 1950s, is to be found in the area behind the Livingstone Statue, where mature mopane is present mixed with mwangula (Pterocarpus antunesii), and six species of mubwabwa (Commiphora spp) amongst others.
The Zambezi fringes, as with most river systems, support a corridor of riverine or riparian woodland. This narrow belt forms a woodland margin either side of the river, and its standard species composition across most of south central Africa suggests that its distribution is a historical remnant of a much wider woodland forest covering the area. The stretch of river upstream of the Falls, eg. along Zambezi Drive to Big Tree on the southern side, is a typical example of this woodland corridor.
The famous Victoria Falls 'Big Tree' is a Baobab (Adansonia digitata), and not the largest at that, although this is an old and impressive specimen. There are several more baobab trees close to the 'Big Tree', and they are a popular source of African myth.
The river is fringed with Waterboom species amongst others, such as the 'sausage tree' (Kigelia pinnata), with its large sausage shaped seed pod, which floats on water to aid dispersal. Riverene fringes include aquatic and flood tolerant river margin plant species such as reed (Phragmities mauritianus) and papyrus (Cyperus papyrus).
The Rain Forest
The famed "rain forest" of the Victoria Falls National Park on the Zimbabwean side of the falls is in effect an extension of the riparian woodland/forest, enriched by the constant sprays from the Falls. There are nearly 150 tree/tall shrub species occurring within this habitat, plus over 50 shrub and 150 field/herb species. Together with grasses, sedges, ferns and other groups the total is over 400 plant species. Many of the tree specimens in the Falls Park are identified with small metallic name plates, viable from the paths.
The rain forest supports a variety of tree species, of which the African Ebony (Diospyros mespiliformis) is probably the largest and most striking, with its straight trunk, dark bark and alternate oblong leaves. Another similar species, and one of the common trees of the rainforest is the Red Milkwood (Mimusops zeyheri). Four species of large fig are present, two of which are more easily distinguished - the hairy leaved Cape Fig (Ficus capensis) and mututa (Ficus ingens) which is a strangling creeper which eventually kills the tree which supports it. Also found are two species of Waterbooms (Syzygium guineense and S. cordatum), with leathery opposite leaves (elliptic and cordate shaped respectively). The hybrid Waterboom (S. guineense barotense) is the commonest tree in the rainforest, and has become so due to its ability to spread vegetatively, with shoots from its roots producing new trees. Another imposing tree is the Natal Mahogony (Trichilia emetica), with its pinnate leaves. Not so common is mulombelombe (Strychnos potatorum) with its opposite, three-veined leaves.
Of the smaller tree species, the African Olive (Olea Africana) is present, with alternate, narrow, lanceolate leaves. The second most common tree species is the Wild Date Palm (Phoenix reclinata), which together with the Waterboom and Milkwood species make up over 80% of the total tree species in the rain forest.
The shrub layer includes Feretia aeruginescens, a straggling shrub producing clusters of delicate pink flowers and spherical red fruit. Pavetta cataractarum, named after the Falls, produces masses of tubular white fragrant flowers, and Hibiscus calyphyllus produces a large yellow flower typical of the Hibiscus family.
The unique micro-climate created by the spray from the Falls particularly favours smaller moisture loving plants, especially the herbaceous ground flora which contains some of the rare and unique species to be found in the rain forest. Throughout the year it is possible to find flowering examples of the bright yellow flowered little Gentian (Sebaea barbeyana), the blue flowered Lobelia spp and the bright mauve flowers of Nesaea floribunda. The early rains in November bring the Fireballs, (Haemanthus filiflorus and H. multiflorus), known locally as the 'red hot pin cushion', with their large globes of many slender red tubular flowers. In December the ground orchid Calanthe corymbosa develops its large white flowers, the wild gentian (Chironia palustris) adds its pink flowers and the Flame Lily (Gloriosa superba) its red and yellow flowers to the natural display. Ferns, notably the Maidenhair (Adiantum capillus-veneris), which is common, and the near endemic Cheilanthes farinose, with its striking sulphur silver yellow under-surface to the fronds, can be found throughout the rain forest area at any time of year.
An 'alien' (non-natural to the area) species, Lantana camara, is a problem in the park and surrounding areas of the Falls. Introduced from South America as an ornamental garden creeper, it is a highly aggressive species which out-competes the local indigenous flora, and without active management is overtaking large areas of the park at the exclusion of the natural species. Another alien invader, the Sword Fern (Nerphrolepis cordifolia) is also of increasing concern.
The Batoka Gorge
Downstream of the falls the steep granite rock walls of the gorges, where not too precipitous, support mixed deciduous woodland typified by small to medium sized paper bark trees, which form especially on the moister shady sides of the river gorge. On drier, more exposed, rock faces, tree species give way to plant communities typified by the Aloes (Aloe chabaudii and A. cryptopoda).
Trees in the gorge are characterised by three species of paper bark tree, a group identified by their smooth papery bark which peels off the trunk in thin layers. The Paperbark Corkwood (Commiphora marlothii) is the most common, and is recognised by its velvety leaflets, 3-5 pairs per leaf with terminal leaflet, and greenish bark peeling in large yellow pieces. The flowers are small inconspicuous heads, produced Oct/Nov, the small fleshy fruit forms Nov-Jan and is edible fresh or as a preserve. The less common Paperbark Falsethorn (Albizia tanganyikensis) has similar leaves but is noted by its creamy white bark peeling off in reddish-yellow pieces. The flat brown pods are toxic. The Large-leaved Star Chesnut (Sterculia quinqueloba) is identified by its lobed, broadly oval-shaped, leaves which are clustered near the ends of the branches, and which turn a beautiful yellow-gold in autumn before they fall. It also has the smooth bark typical of the paperbark group, usually creamy pinkish-brown. The flowers are produced on inconspicuous heads, produced between Jan-April. The fruit, a distinctive five-lobed globe shape matures between May and Sept.
The rugged slopes of the gorge are also favourable habitat for two rare and localised tree species which can be found - Entandrophragma caudatum and the Propeller Tree (Gryocarpus americanus) which is of note for its wind-borne seed with two lobed wings which propel the seed to the ground.
Of the shrub species found in the gorge, Balaria matopensis is locally abundant on the upper slopes and is identified by its attractive blue flowers. On rocky outcrops the rare Hibiscus prateritus finds a foothold with its small scarlet flowers. The Everlasting Plant (Myrothamnus flabelliflius) is noteworthy for its adaptation to the seasonal variations in moisture which allow the plant to almost completely dry out, only to revive itself when water returns.
In more rocky sections of the gorge, where shrub and tree species are unable to survive, aloes add a splash of colour with their spikes of brick-red flowers in July and August. Aloe chabaudii is the more common and most widely distributed aloe in Zimbabwe. Aloe cryptopoda is less common and has the distinction of being discovered by Livingstones 1859 expedition.