The Smaller Things In Life

Stapelia Gigantea

March 20191

 

‘Our plant of the month for March is Stapelia gigantea also known commonly as ‘Giant Stapelia’,  ‘Giant Carrion Flower’ (English), ‘Aasblom’ (Afrikaans), ‘ililo’ or ‘uzililo’ (Zulu).  The plant is native to the arid and semi arid areas of south eastern Africa and can be seen in full flowering display at Mantuma camp in uMkhuze.

 

The stems of the plant are succulent, four angled, flattened on the angles and edged with small teeth.  In summer, it bears large star-shaped five-petalled flowers up to 25 cm (9.8 in) in diameter. The flowers are red and yellow, wrinkled, with a silky texture and fringed with hairs, that can be as long as 8 mm (0.3 in).  The flowers also have the smell of rotting flesh, which acts to attract the flies which pollinate them.  Said to have one of the largest flowers in the plant kingdom.

 

The plant is used in traditional medicine to treat hysteria and pain.  Also used in sorcery as a poison and is reportedly capable of causing death.

 

Stapelia gigantea is widely cultivated and can become invasive when introduced in arid and semi-arid environments’

 

Sources: Pooley, E.  A Field Guide to the Flowers of KwaZulu-Natal and the Eastern Region.  Natal Flora Publications Trust and Wikipedia.

The Smaller Things In Life

How many times have you wandered through the bush and brushed through a spider’s web?

Like most of us you’ve either:

• brushed the sticky filaments off and continued on your way with little attention given to the web’s inhabitant, or

• rebounded off the springy supporting lines and rapidly reversed at sight of the (usually large) owner.

Doubtless you will have come away from the encounter with the perception of spiders as solitary animals firmly reinforced. In general this perception is valid, most species of spider are solitary in habit, but as with many things in life there are exceptions to the rule.

One exception is the community nest spiders which belong to the genus Stegodyphus. Six species occur in South Africa (Dippenaar-Schoeman, 2014), of which two may be encountered in uMkhuze Game Reserve.

These are S dumicola and S mimosarum. Both species build large communal webs on vegetation. These are constructed of cribellate (teased) silk with thick supporting filaments mooring them to vegetation. A dense mass of silk is spun to form a refuge where the spiders shelter from the elements and predators.  

 

When an insect becomes trapped in the web a number of spiders will rush out to overpower it. The prey is then shared by the spiders.

spider1

Figure 1: Community nest spiders consuming a fly.

Spider

Figure 2: Community nest spiders dismembering a grasshopper.

As with most spiders there is a considerable difference in appearance between males and females (sexual dimorphism). The males tend to be much smaller than the females and may have different colouration or shape.

It is most likely therefore that the spiders shown in Figures 1 are all female.

 

Written By: Pat Jenning, Honorary Officer uMkhuze Game Reserve.

Sources: Biodiversity Explorer, Dippenaar-Schoeman, A. 2014. Field Guide to the Spiders of South Africa. Lapa Publishers. Leroy, A. and Leroy, J. 2003. Spiders of Southern Africa. Struik Publishers. The Spider Club

Knob Thorn

knob thorn

The Knob Thorn is a slow-growing, deciduous tree that grows 5–18 m in height, with a long cylindrical shape and rounded crown. The common names in English and Afrikaans refer to the very characteristically knobbed thorns on the trunks and branches.

knob thorn bark

The knobs are very conspicuous, making the Knob-thorn tree easy to identify. Flowering is erratic and occurs between August and November.

knob thorn flowers

Flowers begin as 70-100 mm long elongated spikes of reddish-brown buds at the end of branchlets, turning creamy-white when fully open, totally transforming the tree. Rounded, butterfly-like double compound leaves form in late spring.

knob thorn leaves

The fruit is a long, thin pod about 100 mm long and 13-25 mm broad. They are initially a reddish-purple colour darkening to a dark brown and fall to the ground before they split open.

knob thorn seeds

Knob thorn is a species with a wide distribution range, occurring from Tanzania southwards to KwaZulu-Natal. They grow in various savanna regions, often at low altitudes, and in rocky areas, on well drained soil. It is drought- and termite-resistant. Although the Knob-thorn is very thorny, it is a highly nutritious tree, with the thorns merely limiting the amount of time animals feed on it.

Elephants eat the branches, leaves and shoots, kudu browse the leaves and shoots and giraffe, monkeys and baboons eat the flowers. Knob Thorn flowers are a dietary component for giraffes. Its flowers contain almost three times as much condensed tannin as leaves. Giraffes consume large quantities of flowers resulting in distinct browse lines on the trees. Giraffes have a very unique relationship with this acacia species – it is believed that they pollinate the trees.

Written By: Honorary Officer uMkhuze Game Reserve