Baobab bark can be smooth, or deeply folded, or resembling molten wax slowly creeping down the side of a candle, as in the image above left. Grey or grey-brown is the normal colour, sometimes tinged with a coppery hue.

Elephants feed on Baobabs!

They strip bark off and sometimes dig into the pithy wood with tusks, finding the bark and under-bark fibres nutritious. But Baobabs have a remarkable ability to survive extensive damage to their bark, regenerating, but always bearing the scars of elephant attack.

Ring-barking is fatal for most tree species in Kruger, but Baobabs have survived elephant abuse for thousands of years. Drought is a major cause of Baobab mortality, and severe elephant damage to bark may contribute to stress by reducing the tree's ability to conserve moisture in its trunk.

People learned long ago that the fibrous under-bark layer can be soaked in water and twisted into a cord that is durable and tough.

Three forms of compound leaves?

Leaves on mature Baobabs are digitally compound, with 5 or more leaflets, but . . . leaves on juvenile plants may be simple, or trifoliolate or digitally compound.

The image above shows a digitally compound leaf. Note that the apex of each leaflet tapers to a sharp point. Margins are entire. The petiole is long, up to about 12 cm, and petiolules are either absent or minimal. The terminal leaflet is the largest.

This digital leaf design gives the tree its species name digitata. Incidentally, the genus name Adensonia honours Michel Adanson, a French botanist and naturalist of Scottish descent, who lived from 1727 to 1806.

Leaves are usually spirally arranged at branch ends.

Try crushing some leaves and sniffing the sharp, strong smell!

While looking at leaves, also try snapping off a twig. It does not snap, because of the fibrous nature beneath the bark, and that fibrous design applies to the trunk and the entire tree.

The image on the left, above, shows a simple Baobab leaf on a young plant. Until the characteristic trunk of the tree starts developing, the simple leaves can mislead the amateur botanist seeking to identify the plant.

The three leaf forms shown above right were taken from the same plant on the same day, illustrating how confusing young Baobabs can be.

A one-night show!

A flower bud starts to open in a late afternoon. By sunset the flower is fully open. By dawn it is starting to fade. It will drop to the ground during the new day.

Why is the Baobab a one-night bloomer? The energy cost of producing this large, short-lived flower is high. Pollination and fruit-generation is the tree's purpose. It is vital for pollen to be transferred from anthers to a stigma, preferably from flowers on other trees. 

Research has shown that Baobab flowers are receptive to pollination for one night only, and receptivity of stigmas declines from daybreak. Furthermore, each flower is unreceptive to its own pollen.

Daytime visitors seek nectar, but they are unlikely to pollinate a flower.

Bats or hawkmoths?

Baobab flowers appear to be perfectly designed for bats. Navigating by radar, bats must be able to access the flower without entangling foliage, and perch upon a reasonably stable base. Therefore Baobab flowers are at the ends of branches, away from hindrances, hanging on long peduncles, and emitting floral scents. Big, waxy, firm, luminous white petals are sufficiently large and robust landing pads for bats. 

Observations in Kruger Park and Zimbabwe, however, indicate that nocturnal hawkmoths are the primary pollinators, and bat visits to Baobab flowers may be rare or absent. The apparent absence of bat pollinators may be due to the availability of preferred food sources in the sub-region, such as figs.

This contrasts with East and West Africa, where bat pollination is typical. Baobabs have evolved their flower design for bat pollination, but that design is no hindrance to geographic variations in pollinator identities.

Neat, rounded displays of stamens on each flower will have hawkmoths moving from flower to flower until satiated with nectar. The flower's stigma-tipped style extends well beyond a flower’s stamens, making transfers of a flower's pollen to its stigma unlikely.  Experimental researchers have found that self-pollinated flowers bear no fruit.

A hawkmoth flying in to its next flower, carrying pollen from a former flower, is likely to deposit some pollen on to the new stigma. Pollination is effective, as evidenced by Baobab trees laden with fruit.

Baobabs deliver modest numbers of flowers each night over a period of weeks. This encourages pollinators to visit the tree repetitively, but also to visit several Baobabs each night, thus enhancing cross-pollination.

Infrared camera traps have also observed bushbabies at Baobab flowers, and they probably assist in pollination. Bees, small moths, ants and other insects also visit the flowers, but they are unlikely to play useful roles in pollination.

Fascinating research on Baobab pollination at:

https://onlinelibrary.wiley.com/doi/epdf/10.1111/btp.13033

A designed-for-purpose pod!

The fruit is a pod with a hard, woody shell covered in yellowish velvety hairs. The fruit is indehiscent, and strong jaws are essential to crack open this cache of valuable nutrients.

Mostly, the fruit will be carried away from the tree before tackling the task. This distributes seeds, but seeds are carried further afield in the digestive tracts of baboons and others.

Cream of tartar?

The dry pulp shown in the image above left is sometime referred to as 'cream of tartar'. The Afrikaans name 'kremetartboom', or cream of tarter tree, refers to this pulp and its similarity to the common baking ingredient called cream of tartar, which is a bi-product of the wine-making process.

The 88 kidney-shaped seeds in the image top right all came from the one fruit on the left. A 1,000 year old Baobab in Kruger may have started with a baboon sitting on a rock spitting out a seed like these!

Seeds are nutritious, rich in protein and potassium, but are more palatable for humans if cooked. Seeds can also be pressed to release a small quantity of oil from each. The oil can be used effectively as an easily-absorbed skin moisturizer and balm, and as an ingredient in cosmetics.

Super-fruit!

Those beautiful one-night flowers, the night-time hawkmoths, the pods developing on the tree, are all designed to end up in empty shells like these. For those with the jaws to access the contents, the pulp contains 50% more calcium than spinach, is high in antioxidants, and has three times the vitamin C of an orange. This is a super-fruit!

Baboons, warthogs and others may eat or discard seeds, but they, unwittingly, disperse seeds effectively.

Interestingly, the European Union approved Baobab fruit as an ingredient in foods, smoothies and cereal bars in 2008, and the US Food and Drug Administration granted safe status to Baobab dried fruit pulp as a food ingredient in 2009.

Baobabs have many human uses. This neatly-cut arched doorway gives access to a storage barn, out of reach of most non-human burglars. Lions could access this cavity, but no lions roam these Makuleke landscapes.

We visited this remote tree in January one year, but found the barn empty. A mid-winter visit might be more rewarding, and perhaps this little room is used as someone's secure sleeping quarters!

Habitable niches can be found in a Baobabs, drawing in many bird species. Mottled Spinetails (Telacaanthura ussheri) and Böhm’s Spinetails (Neafrapus boehmi) both nest in cavities in large, old Baobabs, usually on vertical walls, about 3 to 5 metres above the ground. Nests are cup or saucer-shaped and difficult to spot in darkened cavities.

Humans and Baobabs have lived in close harmony over millennia, and these twins standing together in the late afternoon sun on the northern bank of the Luvuvhu river suggest some human involvement in their origins.

This young Baobab, located far from any other Baobabs, illustrates that Baobab seeds are transported over significant distances before germination, either by animals or humans.

The 'Sagole Baobab’, outside of Kruger Park and between Pafuri and Tshipise (-22.50019 30.63312), is South Africa’s largest tree, with a girth over 10.8 metres, height of 22 metres and a crown diameter of 38 metres.  The trunk circumference is about 33 metres.

The tree has a hollow cavity in its trunk that can hold 20 people, and is a habitat for a rare colony of mottled spinetail swallows.

Carbon dating gives an age of at least 1200 years.

Several Baobab forests exist in northern Kruger, with this group immediately south of the Luvuvhu river. Human habitation close to the river in the distant past may have played a role in the propagation of trees.

Baobab mortality is low once a young tree grows beyond the reach of browsers. The trees are resistant to elephant bark-stripping, but the combination of drought and extensive bark loss may result in death.

Baobab wood is fibrous, soft and spongy and the trunk typically stores a large volume of water, enabling the tree to survive long periods of drought. Baobabs are thus succulent in nature.

But when a Baobab dies and the remaining water in the trunk is lost, the tree collapses into a massive pile of fibres, a sad ending for a magnificent tree.

Majesty!