Succulents of Finsbury Estate

FINSBURY ESTATE SUCCULENTS

Succulents are generally plants that have either modified their leaves or stems as storage organs to enable them to occupy harsh environments or to avoid competition. Very many plant families contain members that could be regarded as succulents but horticulturalists usually concentrate on members of the Stonecrop and Purselane families, and some members of  the Aloe, Granadilla, Oleander, Fig-marigold, Euphorbia and Geranium families. These are the succulents that have been grown and cherished by enthusiasts all over the world since the seventeenth century.

Southern Africa happens to be the richest zone for succulent flora on the entire planet and this becomes quite apparent, I found, if one goes out in search of them on the estate. Just the other day, whilst igniting a grass fire as part of the final block burn for the season, right on the tippy-top of Spioenkop, I stumbled upon a small colony of the oddest looking plants you could imagine (above) growing in the most extreme conditions. Very "mars-ish", I thought, since they occupied the most exposed habitat one could find in this part of the country, and because their flowers certainly looked like they could have been extra-terrestrial! 

I identified it as a Lifebuoy Huernia or Owl's Eye, Huernia zebrina insigniflora, and this marvelous discovery inspired me to concentrate on succulents while doing a site inspection on our boundary with Potato Seed Production in the Upper Majubane Valley the following day. I found 8 species of succulent in bloom and a further 6 without flowers. That's 14 species of succulent in one day on a small portion of Finsbury Estate! Below is a gallery of some of our succulents:

 AIZOACEAE - FIG-MARIGOLD FAMILY

Adorning cliff faces at all altitudes throughout the estate, the striking flowers of the Climbing Vygie, Delosperma cooperi, offer a flash of colour throughout the wet season. In fact, I still saw a few flowering on my "succulent outing" the other day. Besides the flowers, the fleshy leaves are also attractive and, with this species, mat-forming which makes them perfect as a ground cover. The glistening leaves are responsible for the English common name of "Ice-plant" and is caused by the bladder cells that are engorged with water. This species was introduced to some areas in California to stabilise sand dunes in the 60s and quickly became a pest as it out-competed  the indigenous flora. This is because the bladder cells store water but retain the salts once the water has been used and when the plant dies, these salts are deposited in the soil and hamper the growth of other plants except for the next generation of Vygies.

Another species found on the estate, although not flowering now, is the Delosperma sutherlandii, boasting the largest of the flowers in the genus, over 40mm wide. This genus has become so popular in horticulture because it produces many, long-lasting flowers that are suitable for indoor growth and require very little maintenance. Most of the members of the genus are frost resistant, they grow quickly and can occupy almost all habitats.

As its specific name suggests, the Khadia alticola, can be found on the highest altitude plains on the estate, particularly Goudkoppies and Spioenkop. "Khadia" is derived from the Tswana name for a traditional beer, for which this plant is used to enhance fermentation. The flowers can also be found in bloom right through the wet season with a few individuals still open on my "succulent outing" the other day.

APOCYNACEAE - OLEANDER FAMILY

This most fascinating plant, Stapelia gigantea, has many common names including Carrion flower, Starfish Flower or Zulu Giant. The flower, which can measure more than 250mm across, is amongst the biggest in the plant kingdom and produces a pungent rotten-meat odour. The size of the flower, combined with the colour and odour mimicks a carcass which quickly attracts flies which are the plants main pollinators. This species is not very frost resistant so will not be found in exposed positions on the estate except on north-facing cliffs. This individual resides on a rock ledge, concealed by thick bushes and trees, on a cliff just north west above the bulldozer at the entrance to Bulldozer Creek (Unit 21)

Featured in the introduction to this blog, this Lifebuoy Huernia was in the same colony as the one in the introductory photo, but a different colour form, much darker. The common names: Lifebuoy Huernia or Owl's Eye both refer to the round, raised, plasticky annulus that surrounds the mouth of the corolla tube. The flower is just 25mm across and the stumpy, succulent stems only stand up 50mm but form a wide mat of almost a meter squared. As mentioned, this colony can be found growing just above the north-facing cliff face of Spioenkop koppie. In fact, very close to where Nick Moore of Rock solid (unit 22) must have been sitting when he took that fabulous photograph of the Cliff Aloes at sunrise that is such a feature on my lounge wall (check it out about in the middle of the gallery at www.nmoorephoto.photography/landscape/finsbury/ to get an idea of the exposed habitat) 

ASPHODELACEAE - ALOE FAMILY

This photo, also taken on my "succulent outing" the other day was not too far from the colony of Lifebuoy Huernias mentioned previously. Although they tolerate full sun they prefer a cooler, moister environment and are most abundant on the south-facing cliff opposite the Steenkamps' waterfalls walk, visible from the rope balustrade when you are above the forest. These are possibly the most widely cultivated aloes, as garden subjects, throughout the world and were first cultivated in Amsterdam in the 1670s.

I came across this field of Aloe longibracteata on the steep slopes below the cliffs of Potato Seed Production on my Succulent outing the other day, too. These, together with the previous species, are an important food source for our abundant sunbirds during the colder months and even though this was an open grassland, I saw many Double-collared Sunbirds attending these flowers.

Although they flower during the summer months, these little Grass Aloes, Aloe chortolirioides woodiana, were easy to locate on my succulent outing by their unique fleshy, grass-like leaves, although noticeably thicker than the nominate species A.c.chortolirioides. Being a grass aloe, these plants can be completely consumed by fire and rapidly sprout new leaves straight afterwards.

A summer flowering grass aloe, also adapted to withstand fire, which can only be found if you are very lucky, is the Aloe minima. As the specific name suggests, it is a very small aloe, standing 20 or so centimeters, with fine, grass-like leaves, occurring in amongst the grass in grassy meadows throughout the estate. No such luck finding something like this on my succulent outing, I'm afraid, but certainly something a succulent aficionado would love to grow. 

CRASSULACEAE - STONECROP FAMILY

Certainly one of my favourite "trees" on the estate is the Bonsai Crassula, Crassula sarcocaulis, which is very common on high altitude rocky areas, thus making it easy to net on my succulent outing. Most of the individuals I saw still had some old flowers blooming but most had finished flowering by now. These natural bonsais are well adapted for the extreme weather they experience up there on the rocky peaks by being able to withstand temperatures right down to minus12 degrees Celsius, which is abnormal for a crassula. They are also able to withstand frequent and prolonged drought with their extraordinary metabolism that allows normal photosynthesis without much water loss. This is called Crassulacean Acid Metabolism and, instead of the stomata opening in the day to allow in carbon dioxide for photosynthesis, the process occurs at night, minimizing water loss.

Only set to bloom towards the end of winter, I did not encounter any Pig's Ears, Cotyledon orbiculata, on my succulent outing although they are easy to locate on the estate, especially on the cliffs above SPK 10, 11 and 12. The common name comes from the shape of the large, fleshy, ear-like leaves that gather at the base of the plant. A very popular garden succulent that can be purchased from most nurseries in South Africa and abroad. 

Although I have seen most of my Giant Crassula on the slopes of the very area where I enjoyed my succulent outing, I did not encounter any as they finished flowering two or so months ago. When they do flower, though, they are hard to miss because they stand taller than a meter and that huge thyrse of flowers can get to 400mm wide like a huge cauliflower. There was a very noticeable individual on display this year beside the entrance road, on the high bank, between the Spekboom river and Klipspringer hill.

I also did not encounter a Campfire Crassula, Crassula capitella, on my little excursion. Not because they are rare, but because they have yet to flower and only stand 300 to 500mm tall. The flowers will be opening soon although they are tucked against the stem, very small and quite hard to see. They are widespread in rocky grasslands at medium and high altitudes throughout the estate. 

This compact little succulent stands only 30 to 100mm tall and inhabits high altitude areas with very shallow soils and stunted grass. It is a Crassula compacta and it is almost a dwarf version of the previous species. This species is a popular indoor pot plant and is rather hardy so good for beginners. The more shade the plant is growing in, the greener the leaves become, although full sun is necessary for a few hours each day regardless. Also, like most succulents in pots, be sure to only water the plant once the soil it is dwelling in is dry to the touch, to avoid over-watering.

Another dwarf succulent very suitable for pot cultivation, a Hairy-cushion Crassula, Crassula setulosa, with its triangular, sessile, opposite leaves that are 90 degrees from the previous and following pair. This species is even easier to grow than the previous species because it can tolerate any soils and full shade or full sun. It is also much more common than the previous species and is easy to find on any high altitude rocky area on the estate. They flower, though, in the latter half of summer so I just missed the flowers on my little succulent excursion the other day. It also forms mats which make it an ideal succulent for growing on a living wall.

This is a Crassula pellucida and it is extremely variable in form although all forms prefer more shade and moisture than most other Crassulas. Find them either on the shaded side of high altitude boulders or forming large mats on horizontal rocks on the sides of forested gorges. All five varieties of the species are popular horticultural subjects.

The maroon foliage of this Crassula swaziensis is a result of a lack of water. The plants are green when water is more abundant but this season we had around 200mm less rainfall than our annual average since 2010, so we expect a particularly dry winter this year. This species is just beginning to flower right now and I took this photo on my little succulent excursion the other day. The plant is extremely common in any rocky area at all altitudes on the estate.

Certainly one of the most attractive succulents to be found on the estate, a Crassula alba growing from the shaded bank of the KLF road between us and Haartebeesvlakte. The specific name is rather misleading because "alba" means white and no part of the plant is white except for the petals, and most crassula flowers are completely white. Anyway this beauty is not as common as most the other Crassulas and flowers in mid summer, so I did not encounter any on my excursion. They are popular horticulture subjects like most of the genus but are only grown from seed, which they fortunately do easily. They are one of the species that has shown positive results during testing as a "green roof" subject and may already be used for such in KwaZulu Natal.

This is certainly one of the most common and widespread of our crassulas on the estate. It grows in medium and high altitude grassland and sprouts from a woody rootstock each season. The flowers are yellow in the southern part of its range but are white in the northern part. We are on that dividing line so we get an equal number of white individuals as those that are yellow, even growing amongst each other! They flower in mid summer but I did manage to encounter a few shriveled individuals on my succulent walk the other day.

I also took this photo on my walk the other day and it shows the beautiful orange inflorescence of this Kalanchoe rotundifolia. The genus is very popular as horticulture simply because the flowers are so attractive and the inflorescence is in bloom for months with one or two flowers opening at a time. Even if you pick the flower and put it in a dry pot, the flowers will still all open one or two at a time until they have all flowered. These splendid little succulents are also very common on the estate and can be found in a variety of habitats and at all altitudes.

Wow! One of my very favourites, a Kalanchoe thyrsiiflora, photographed on my excursion the other day. They are usually large, imposing and easy to spot but this individual must be the biggest I have yet seen on the estate. The plant stood about 1,6 meters tall with the inflorescence 120mm wide at it's widest! Once the flowers  have been pollinated they produce masses of tiny dust-like seeds that are spread by the wind from the dried inflorescence that makes for beautiful dry flower arrangements as well. A close relative, K. luciae, is a very popular garden subject but this species performs just as well. 

Now the bad boy of the bunch, an exotic, very invasive Prickly Pear, Opuntia ficus-indica. A truly incredible plant that originates in meso-america, the Prickly Pear has found its way around the globe and is used for burn treatment and diabetes treatment in medicine but mainly for its delicious fruit (pictured, the pink bit) and edible leaves (cladodes). The fruits have the highest content of vitamin C then in any other plant and was used in the old days to mitigate scurvy amongst sailors.. Unfortunately they have incredibly invasive tendencies and have become a serious problem plant almost everywhere it has been introduced and escaped into the wild. In the 1920s, Prickly Pear became a serious problem in the Eastern Cape and the release of Dactylopius opuntiae, a cochineal bug, proved a successful bio-control agent. Currently, the populations of Prickly Pear are controlled in most of the country's hardest hit areas by a combination of bio-control agents like the cochineal bug, the Cactus moth, Cactoblastis cactorum and the stem-boring Weevil, Metamasius spinolae. The individual in the photograph was the mother plant in an invasive colony that I found in the rocky crags on the slopes of Little Joker Koppie, overlooking the Majubane valley (see Tranquility unit15 in the distance). I dealt with the colony with a herbicide which was successful but will require follow-up operations in the future. This is only the second colony that I have found but individuals pop up every now and again and when I find a single plant, I uproot it and rub it to a paste on nearby rocks because if you just throw a small piece in the ground, it will take root and grow.  

A succulent outing is a great idea and I thoroughly enjoyed it. When you finally get a chance to visit us again, give me a shout and I will gladly take you on a guided succulent hike. Stay safe. Maintain social distancing and all things necessary to help defeat this global challenge. Good luck!

Finsbury Dung Beetles

DUNG BEETLES OF FINSBURY

I got a message from Ian Keogan from Finsbury House (unit 23) recently, asking for me to feature Dung Beetles in my next blog. Well, I checked my list of beetles for the estate and found that I had quite a bit on the interesting little creatures. So I thought that it would be a good idea to oblige, especially since they have also always fascinated me as well.

Dung beetles belong to the largest order of insects, the beetles, Coleoptera, with almost 400 000 species so far described. They are typical beetles and are grouped mainly in the family Scarabidae but also in the Geotrupidae. Morphologically, they are typical scarabs like the Fruit Chafers featured in my previous blog but what makes them different is their adaption to eating the exrcement, almost exclusively, of larger mammals. The larvae are regarded as vegetarians because they eat the undigested, dry vegetable matter found in mainly herbivore droppings. The adults not so much because they eat the liquid portion of fresh herbivore droppings which consists of a soup of the living and dead microorganisms used by the herbivore, in it's gut, to help digest vegetable matter.

Dung beetles detect their food mostly by smell, although sometimes they just hang around a herd of animals and wait for them to evacuate their bowels. Their smell is well developed as anyone who has enjoyed a "boskak" (not sure what else to call it so I will resort to army talk) in the game rich areas of our beautiful country will attest to. It is most awkward to watch and hear the beetles arrive from downwind, en masse, and promptly begin work while one is still squatting! This quick response, by the beetles, is necessary because of the intense intra and interspecific competition between dung beetles on a single pile of excrement. This is easy to observe on a fresh elephant dropping in the lowveld at the right time of the year where literally thousands of individuals of a bunch of species can be found. Because of this competition, species have split into groups that handle the situation differently:

The telecoprids are the most noticeable to us because they are ones that arrive at the scene and quickly cut a chunk off the pile of excrement and form it into a ball and hastily roll it away from the area. A good example, although I have not seen one here on the estate, is the Large Copper dung beetle, Kheper nigroaeneus, pictured above, that I photographed in the Lowveld recently. Although they have evolved the behaviour of rolling balls away to avoid competition with other species, they often arrive at large mammal excrement piles in such numbers that it can be quite a sport to watch them frantically rolling balls and defending them against others who try to steal them. They flip their opponent over onto their backs and while the opponent attempts to right himself, they try to roll the ball as far away as possible to avoid further confrontation. This goes on until the winner manages to sneak off with the ball.

An, as yet unidentified, species breaking up the droppings of a large male Warthog in the Whisky valley near W9.

In amongst all this mayhem, this busy time is also the time for males and females to find each other and form bonds. Initially, male and female telecoprids roll a ball away until they find a suitable spot to bury it. Once buried, they eat it together and mate. This ball is called the Nuptial Ball, and eating it together is very much like getting married. Once mated, they will attend another pile of excrement, roll a ball and bury it at the bottom of a relatively deep hole where the female will deposit a single egg in it. They will repeat this process until the hole is filled with 3 to 4 balls, each with an egg laid within.

 The larva, a fat white grub, hatches within this secure environment and eats the ball out from the inside, leaving the hard, dried muddy covering intact. The larva then pupates within the ball and digs it's way out when it emerges. Interestingly, the larva whose egg was laid last into the top ball in the pile in the hole is the one who hatches and pupates first so when the adults emerge from the balls below, they don't experience too much traffic trying to bypass the others above.

One thing I remember when walking through the bush was how often I found how these balls had been dug up by Honey Badgers who had extracted the grub or pupa as a tasty morsel. The Honey Badgers seemed to have an uncanny ability to find this buried treasure!

The paracoprids arrive at the scene and immediately burrow a hole beneath or beside the pile of excrement in which they retreat while they deal with the stuff. A good example of a paracoprid is the above Rhinoceros Beetle, Heliocopris atherstoni, a hornless female. Once they have dug a hole beneath or beside the pile of excrement, they stuff the chamber with excrement, periodically laying an egg. The female beetle remains in the chamber with the offspring to protect them, particularly from parasitic insects, until they emerge as adults. A very rare example of parental care amongst insects.

The endocoprids arrive later and bury themselves into the pile of excrement and effect all activities in situ. The fresh piles of excrement will house the adults while the drier piles contain eggs.

And the kleptocoprids are like cuckoos because they lay their eggs in a ball that has already been formed and is being rolled away by its unsuspecting owner.

Whatever method they employ, the environmental benefits of the presence of dung beetles is most notable. Paracoprid dung beetles are released together with cattle or goats in rehabilitation projects in old open-cast mines in South Africa to help with aeration of the soil and with water absorption. A single beetle can bury more than 1000 times its own body weight of excrement in 24 hours. The burying of cattle droppings returns 90% of feacal nitrogen to the soil in the summer. Interestingly, termites fulfill this function in the winter time when the dung beetles are inactive. It has also been found that uptake of the essential minerals, nitrogen, phosphorus and Sulphur in plants was 80% greater in soils where dung beetles were active. 

One look at the spatula-shaped head and the spines at the end of the tibia of this dung beetle show that it has been very busy digging. The ability of dung beetles to dig into very hard, dry soils to bury their collected dung, makes them ideal candidates for environmental rehabilitation projects.

They are also very important in the control of fly populations. Here's an interesting story about Australia and dung beetles:

Modern man arrived on the huge island of Australia around 40 000 years ago to find it filled with strange animals, big and small, of marsupial persuasion. Within 10 000 years almost all of the larger animals were wiped out by this invasion of human beings together with the larger species of dung beetle that cleaned up their mess, leaving only the smaller dung beetle species that utilised the droppings of Kangaroos and Wombats. 

This huge, up to 40mm in length, female Rhino beetle, Heliocopris hamadryas, is the only species of dung beetle that specialises in the excrement piles of large pachyderms like elephants and rhinos that can adapt to handling droppings of smaller herbivores. The other specialists of pachyderm dung would have become extinct together with their food producing hosts in the Finsbury mountains. This species is also able to emit a screeching sound when it is handled, a result of stridulating their thorax against their elytra. 

Then, very much later, in the 1800s, man introduced cattle onto this massive island. A single steed produces at least 12 piles of excrement a day. Although the grass surrounding these patties tends to go greener, it is unpalatable to further cattle grazing and thus is not utilised. Australia was losing around 200 000 hectares of grazing land to this every year. To add to this, these patties were optimum breeding sites for flies and parasitic worms. Roughly 3000 flies can breed from one cow's patty in a period of 2 weeks! In fact, prior to the successful introduction of dung beetles from South Africa, Bush flies, Musca vetustissima, were so problematic that it was illegal for restaurants and cafés in Australia to offer outside dining unless a designated area was enclosed by fly-wire.

In 1968, Dr Bornemissza, an entomologist and ecologist, introduced dung beetles, originally from Hawaii and then from South Africa, into the cattle lands of Australia. The beetles spread 50 - 80 km per season so by mid 1970, they were established over an area of approximately 400 square kilometers, including 2 islands, 10km and 30km offshore respectively. Ultimately, 29 species, out of 85, were successfully introduced into the country. The project is still ongoing to this day.

This photo of a Spider Dung beetle, Sysiphus sp, taken on the slopes of the Steenkamp's valley, clearly shows the club-tipped antennae that is divided into 3 segments, a feature unique to Dung Beetles from the Scarabinae subfamily.

 

This photo of a dung beetle, probably from the Heteronitis genus, shows the distinct shape of the front legs, flattened like a spatula for the smoothing down of the dung balls, and the spikes at the end to help the beetle to dig into hard ground. These dung beetles prefer the dung of hindgut fermenters, like Zebra and Warthog droppings on the estate.

On quite a few occasions I have spotted dung beetles rolling living and dead millipedes along the ground. According to my research, there are a couple of species in the Sceliages genus that are predators and scavengers of millipedes. They can detect the scent of the defense allomones excreted by millipedes when they are molested by predators or trampled by larger animals. The beetle will then roll the millipede to a suitable place and then straddle it and use its modified forelegs to disarticulate it into sizable chunks to bury. There have been many records of these Dung beetles stealing millipede prey from the Millipede Assasin, Ectrichodia crux, from the Reduviidae (see Jolly Season 2018 blog) 

A Spider Dung Beetle, Sysiphus sp, molding a ball of dung from an Eland dropping high above Finsbury House. Unlike all other dung beetles that roll their ball with their hindlegs, these Spider dung beetles do so with their forelegs (They obviously don't mind the smell as much, Har Har!). Some species of Sysiphus hang their ball on vegetation instead of burying it.

A common species on the estate, Scarabaeus rusticus, preparing a ball from a Civet dropping. Although the beetles prefer herbivore droppings, they will also feed at carcasses, the excrement of carnivores and from omnivores like the Civet.

A few interesting facts about dung beetles:

•  A dung beetle was recorded pushing a ball 1141 times it's own body weight, making it the strongest animal on the planet. That's equivalent to an average sized human pushing 6 fully laden double-dekker buses down the road!
•  Most dung beetle species live up to 3 years of age.
•  When the ground is very hot, dung beetles stand on top of their ball to allow their feet to cool down.
•  One South African species, Onthophagus gazella, navigates at night, using the milky way for direction finding. The only known animal to do this. Most dung beetles use the sun or moon for navigation.
•  A whole array of mite species use dung beetles as transport between dung patties as they cannot fly themselves.
•  Burrowing owls in the Americas use dung to attract dung beetles which they prey upon.
•  Ancient Egyptians worshipped dung beetles as their god, Khepri, the god of the rising sun who renewed the sun each day and rolled it across the sky.

Well folks, again I wish you all the best there in your homes. This virus thing is getting a little long in the tooth now and I wish, together with about 7 billion others, that it would end already! Good luck!