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!