A tale of red orchids and butterflies, on a mountain in the heart of a city.
The city of Cape Town, in South Africa, lies at the southwestern tip of the African continent. Also known as the ‘Mother City’, it has been rated by both the New York Times and the Daily Telegraph as the best place in the world to visit.
Cape Town is famous worldwide for its pleasant Mediterranean climate and well-developed infrastructure…within a stunning natural setting. Home to over 4.6 million people, it is one of South Africa’s largest cities and main economic centres — but if you look towards its centre, you will find the wild and rugged Table Mountain, rising sheer from the bowl of the city below.
Though in the heart of the city, the Table Mountain is a whole different story. Clouds swirl around the summit plateau and its rugged crags, reaching over a thousand metres above sea level. This is most often seen during the summer months when air from southeaster winds is driven upwards and cools, forming a layer of cloud that is often present during otherwise clear weather — which locals have nicknamed the ‘tablecloth’.
The Khoe name for Table Mountain is Huri ǂoaxa or Hoerikwaggo, meaning the ‘mountains of the sea’. Its towering heights are visible from most parts of the city, acting as a waymark that keeps travellers from getting lost.
Zoom out to a more geographical scale, and you’ll see that it forms part of the Peninsula mountain chain — a chain that extends to Cape Point at its southernmost extent. The end of this rugged Peninsula is known as ‘the Cape of Storms’, and not without reason. The name ‘Cabo de Tormentas’ was first penned by Portuguese explorer Bartholomeu Dias after he sailed around what is now known as the Cape of Good Hope in 1488. The exposed peninsula experiences many wild winter storms as cold fronts travel in from the west off the Atlantic Ocean.
The Cape Peninsula sits at the heart of the Cape Floristic Region biodiversity hotspot, with Cape Town regarded as the most biodiverse city on earth.
And, high up on Table Mountain, grows one of South Africa’s most iconic orchids: the Red Disa.
There is a Swedish story that talks about the reign of Sigtrud, King of Sveas, during which a famine befell the land. The peace and prosperity during King Sigtrud’s reign led to an increase in population, until the lands could no longer support its people.
To end the famine, the king and his chieftains decided to make human sacrifices to Odin, the Allfather. The sick, elderly and the handicapped were chosen to be sacrificed.
But when Disa, the daughter of one of the chieftains heard about this, she was agitated. She mocked the king and the chieftains and boasted of being wiser than any of them. “Oh, really?” the King remarked. “Let’s see how far your wisdom goes.” And he challenged her to an impossible task: she was to present herself to him neither naked nor dressed, neither riding nor walking, neither within a month nor within a year, neither during day nor at night and neither when the moon was waxing nor when it was waning. Disa was clearly in a spot, but rather than give up, she sat and thought and rose to the challenge.
On the third day after Yule, with a full moon in the sky and the dusk not yet given way to night, Disa arrived before the King. She had one leg over the back of a deer and the other leg balanced on a sledge that was pulled by two men. And covering her body was nothing but a fishing net.
The King had to admit defeat. Disa had arrived at a time which, by their calendar, was not part of a month. The full moon was neither waxing or waning, Disa had come neither riding nor walking, and while she wasn’t naked, one couldn’t exactly say she was dressed either.
Having won the challenge, Disa was hailed as the new queen. The sacrifice was cancelled, and a part of the population was made to migrate northwards instead.
Members of the genus Disa are thought to be named after Queen Disa, and the reason becomes clear when you look. Known scientifically as Disa uniflora, the Red Disa blooms during mid-summer when Cape Town’s heat is at its most intense. And, the huge red blooms are delicately marked akin to Queen Disa’s fishing net.
As for the second half of the name, ‘uniflora’, when translated from Latin, means literally ‘one flower’. However, this species epithet is something of a misnomer for Disa uniflora, because one plant can produce multiple blooms at the same time.
This error might have arisen when Swedish botanist Peter Bergius was scientifically describing the species. He was given a dried specimen of the Red Disa to describe it from, which was naturally not as good as seeing one in its natural habitat. Disa uniflora had its name changed to the perhaps more apt Disa grandiflora at some point, but the name was changed back later. There’s a taxonomic tradition of keeping the first species epithet as the accepted name.
It is a long, hot and sweaty climb to reach the Table Mountain plateau at the height of summer. A popular route you can hike starts at the world-famous Kirstenbosch National Botanical Gardens and goes via Skeleton Gorge. Nobody knows how this mountain ravine got its name, or indeed who the skeleton actually was.
It is best for you to begin this adventure early, while temperatures are still relatively cool. You begin the hike on gently climbing brick-lined pathways, leading through manicured lawns. These lawns are interspersed with beds filled with the plethora of indigenous plants so typical of the gardens at Kirstenbosch. Sunbirds and sugarbirds flit between the vivid blooms of flowering Proteas and Leucospermums.
You follow the green signs to the outer reaches of the garden, at which point the trail leaves onto the lower eastern slopes of Table Mountain itself. These slopes are clothed in afrotemperate forest, providing cooling shade. Here, the path becomes much steeper, and you can ascend quickly up a series of winding steps, wooden ladders and rocky scrambles.
Suddenly, you emerge above the tree line at the top of Skeleton Gorge. Beyond the forest, the Mountain of the Sea is clothed with fynbos, a fine-leaved shrubland that is both fire-prone and fire-dependent.
Our beautiful Red Disas grow at high altitude on the mountain, deep in forested kloofs, on wet cliff faces or along stream banks. As you pause to enjoy the view across the Hely-Hutchinson dam on top of the mountain, suddenly a large butterfly lands on your red T-shirt.
Its wings are white, blue and chocolate brown. What kind of butterfly is this? Why is it visiting your clothes?
The Pride of Table Mountain butterfly (Aeropetes tulbaghia) is strongly attracted to bright orange and red. It will even land on red or orange clothing a person may be wearing. This beautiful butterfly is one of the largest found on Table Mountain. Despite its name, it is found across South Africa, Lesotho, eSwatini and northwards to eastern Zimbabwe. There is just one generation of these butterflies breeding per year, with the adults being in flight during the southern hemisphere summer from November to April.
Which is important to take note of, because the Pride of Table Mountain Butterfly is the Red Disa’s only pollinator. Without the butterfly, the Disa would soon die out.
The year was 1992, and two scientists were busy putting up coloured, syrup-filled paper discs. These were ecologist William Bond and pollination biologist Steven Johnson, and their aim was to see which flowers attracted butterflies and which didn’t. More specifically, they wanted to know which colours were preferred by the Pride of Table Mountain butterfly, if at all colours were the way it chose where to dine.
People had long known the butterfly to be the Red Disa’s only pollinator — the story of that goes back to a German-born South African botanist by the name of Rudolph Marloth, who caught a Pride of Table Mountain butterfly and found Red Disa pollinia attached to its legs. There are other plants with red or orange flowers that also bloom at the same time, and which are also pollinated by the same butterfly. These include the red succulent Crassula coccinea or the summer-flowering Mountain Pipes, Tritoniopsis triticea.
But are the colour of these flowers a coincidence, or is there a connection between red-orange and the Pride of Table Mountain? That’s what Johnson and Bond were aiming to find out, by sticking up model “flowers” of paper and honey-syrup.
The results, as you may have guessed, were affirmative. Pride of Table Mountain butterflies were attracted to red discs more than to those of any other colour — as indeed they were to red flowers, red T-shirts, red caps, and anything else red. What’s interesting is that many of the red- and orange-flowered plant species aren’t closely related. Each of them evolved independently to attract the same butterfly species — forming what is known as a pollination guild: a guild of flowers that all bloom in similar colours to attract the same specific pollinator. If T-shirts were pollinable, they’d have become part of that guild too.
The Red Disa and its summer-red relatives are just one pollination guild, with many other examples found across South Africa’s highly biodiverse Cape Floristic Region. This insight into plant pollination from Cape Town’s Table Mountain highlights the delicate nature of these highly complex ecosystems. The loss of one species could wipe out a whole guild.
Deep in the heart of a city, high on the Mountains of the Sea, the survival of the guild is dependent on the existence of one extraordinary butterfly.