So to start with: what are Senecios? They're a kind of plant, of the daisy family. The daisy family is a huge family and it includes lots of plants that are not at all daisy-like, but that are nevertheless all related. The members of the Daisy family have characteristic flowers, where what appears to us to be a single flower is in fact a collection of many flowers. In the typical daisies there is a central 'disc' in which a certain kind of flowers, disc florets, occur, and around these is an arrangement of a different kind of flower, the ray florets. This is the 'daisy-type' flowerhead. In other plants of the daisy family, the ray florets are absent, and only the central disc florets are developed. This is the 'thistle-type' flowerhead, and it is usually a shaving brush-like structure. In the Senecios, both of these types of flowerhead appear. Some have typical daisy flowers, while others have thistle-like or brush-like flowers. In the case of the succulent Senecios, most of them have thistle-like flowerheads.
The genus Senecio is a huge one that occurs, as far as I know, all over the world. Apart from the flowers, the plants themselves in the Senecio genus are incredibly diverse in their shapes. Most of them are not especially large and spectacular, but they all have a charm of their own, and they are extremely fascinating in their physical diversity, especially if they are compared with each other and with other plants.
The genus Senecio contains lots of members that are *not* succulents, but a large number here in South Africa have developed succulent properties. First of all - what exactly does 'succulent' mean? Well, you know it when you see it. Succulent plants have thick and fleshy stems and/or leaves. These stems look and feel succulent ... they store water and when they are fully filled with water they appear thick and round, and juicy. They feel soft and yielding to the touch. Also because of the way these stems and leaves thicken, they are more three-dimensional and often develop into very interesting shapes. These interesting shapes, as well as the nice texture many of them present to the touch, make them attractive to people. Of course, some succulents are not nice to the touch, being very spiny, thorny and prickly, but the South African succulent Senecios do not have any thorns, and they are nice and soft and smooth to the touch.
The South African succulent Senecios appear to have come from different groups of Senecios, many of them having developed their succulent characteristics independently of each other. Why have they become succulent? Primarily as an adaptation to the hot and dry climate over most of South Africa. Perhaps certain non-succulent Senecios first enter certain areas during periods of moist climate, and then being in a certain area, the climate starts becoming drier, and the plants also gradually develop ways to cope with the drought. They develop the ability to collect water in their leaves and stems, and in many cases also their roots, during periods of good rains, and their tissues swell with this stored water. Then during periods of drought they can keep alive off their stored water reserves until the rain comes again. In this way they develop the thick and fleshy, juicy leaves and stems, elaborating them in various ways. This possibly happened a number of different times here in South Africa, to a number of different non-succulent Senecio species, which subsequently developed succulent properties to cope with the increasing drought. Then possibly some of them spread out of their original ranges into other ranges and developed into different types. There must have been a degree of 'convergent evolution' between Senecios of different origins, but there has also been considerable speciation of certain lines of Senecios, and there has also been divergent evolution leading to plants with very different shapes, growth patterns and ecological requirements.
The first kind of succulent Senecio I want to talk about is a kind that has developed a minimal degree of succulence. These include most of the time plants that are vigorous scramblers and climbers. They occur mostly on the edges of forests, or in bushveld, savannah and woodland. They have moderately fleshy leaves, and also fleshy stems. Their leaves are still mainly 'flat' and broad. The areas where they grow get good rains during the Summer, but may experience some periods of drought in the Winter, and the moderate degree of succulence of these Senecios help them cope with that. Such species include those called Canary Creepers - Senecio tamoides, Senecio angulatus, and others. These are climbers of forest edges. They are extremely vigorous and fast-growing plants, being able to climb up to the height of the forest canopy, about 20m (65 ft) above the ground, and there their crowns branch out and bear their profuse canary-yellow flowers. They are among the most popular of Senecios for gardens. To this group also belongs other bushveld species such as Senecio pleistocephalus. These climbing Senecios have yellow flowers of the daisy-type, and often flower profusely and for many months of the year. Furthermore their fleshy stems and leaves are attractive. The different species have differently shaped leaves, with toothed and lobed margins, and sometimes with red or purple coloration on the stems and leaf margins. And as I said, they can grow very rapidly and profusely under good conditions, but can also withstand a few months of continuous drought. They like warm climates and cannot withstand severe cold.
Right now I have a plant here at home that I suspect might be one of these Senecios, though I don't know which species. I have collected it in a game reserve half an hour's drive North of Pietersburg, but the plant also occurs here in Pietersburg ... on a small hill just east of our house, and also on another hill at the Northern Sotho Museum, Bakoni Malapa. I haven't seen its flowers yet, and I'm waiting to see if mine flowers. It has very nicely sculpted, toothed and lobed, thinly succulent leaves, and stems with a purple coloration on the growing parts, thickening to about the thickness of a human finger. It grows faster than almost any other plant I've ever seen. I really wish I could find out what species it is. The problem here in South Africa is that we have about thirty thousand species of flowering plants, and most of them have never been described and illustrated in a published book. This is especially a problem with the Senecios ... I have very few good descriptions and illustrations from which to try and figure out what the identity of any plant in Nature is.
The next group of Senecios are far more succulent and far more specialised. These occur in grassland, on rocky hills and cliff faces, and other habitats somewhat drier than those of the previous group. Some even occur in semi-desert or true desert regions, in the Great and Little Karoo, Bushmanland, and Western Cape Sandveld regions. These senecios have leaves that are developed to a greater degree of succulence. They are no longer fat and broad, but now round and cyllindrical ... in some cases even spherical. They thus have a smaller surface area to lose water from, and in some of the species their leaves store enough water to swell to a quite round shape. These leaves are finger-like in appearance, and many of these species have words such as 'finger' or 'toe' as part of their common names. So the species Senecio radicans is often known as 'baboon's toes' and Senecio abbreviatus is known as 'twining fingers'.
One of the least specialised and most common of these finger-leaved Senecios is the Barberton Senecio, Senecio barbertonicus. This Senecio actually occurs much more widely than its name suggests, being found not only in the Barberton region but throughout most of the erstwhile Transvaal. This species also occurs commonly here around Pietersburg. The environment we have here has a hot and dry climate, with fairly good rains in Summer followed by prolonged drought, and temperatures near freezing in Winter. The Barberton Senecio here grows on rocky hills. It is one of the biggest, if not the biggest, of the local finger-leaved Senecios, growing into a succulent bush over 2 metres in height and spread, with a noticeably fleshy trunk, as can be seen at Bakoni Malapa. Its fleshy leaves grow to about 2 inches in length and are light bright green, pointing upwards along the branches. The plant tends to scramble over rocks and other trees and bushes. I believe that in cultivation, given good fertile soil and plenty of water, it can grow much bigger than that ... probably into a treelike plant of over 3m (10 ft) in height and spread. The ones I have growing in bags here at home grow at a rapid rate and throughout the winter as well as the summer. The Barberton Senecio has smallish yellow flowerheads of the thistle type.
The finger-leaved Senecios have flowers of the thistle type, ranging in colour from yellow through different shades of cream to white, and of different sizes, some flowerheads being rather attractive. But the most attractive features of these plants are their leaves and shapes.
Other finger-leaved senecios are smaller, but no less attractive. Senecio ficoides is a species that grows on coastal rocks near the sea. It grows to about 60 cm (2 ft) in height, and it has leaves somewhat thicker than those of the Barberton senecio. These leaves have an attractive bluish-whitish bloom. Other senecios have leaves that blush reddish, especially at the tips, when exposed to intense sunlight. Some species combine a reddish blush at the tips with a powdery-bluish bloom at the base, for a very pretty colour-shading effect, such as in the small Senecio Serpens.
These Senecios differ also in their growth form. Like I said Senecio barbertonicus grows into a free-standing shrub, or one that leans on and scrambles over other plants. The smaller types of Senecio often scramble over the ground, sending up tufts of leaves at intervals, or having the leaves more widely spaced along the scrambling stem, such as in the widespread Senecio radicans, the 'baboon toes'. Senecio laticipes is known as the Rubber Daisy, and it has the appearance of a little bonsai tree with rubbery stems, and small yellow flowers. Senecio rowleyanus is a small climbing plant with its almost spherical leaves arranged at intervals along the trailing stem. It is named 'Buck's balls' in Afrikaans but has the more flattering apellation 'String of Pearls' in English. It is popular in cultivation because of the pearl-like effect of its round leaves.
We also have here at home a Senecio rowleyanus plant growing in a pot ... it's very pretty. I didn't even realise what it was until I saw a picture of Senecio rowleyanus on the 'net ... a few minutes ago!
There is one more growth form in the South African Senecios - where the leaves are lost altogether, and the stem becomes even more succulent and takes over the job of producing food by photosynthesis. As far as I know, there is only one local Senecio with this form - the Senecio articulatus, known as the Sausage Daisy or the Shish-ka-Bob Tacky. It takes this name because its stem is constricted into segments, like a sausage, or the pieces of meat of a Shish-ka-Bob strunk along a stick. This Senecio grows as a trailing plant with its stems lying flat on the ground, the constrcted segments being fat and green, with reddish markings. Young stems bear small leaves but these are soon lost.
These are just a few of the local Succulent Senecio species. As I learn about more of them I will expand this entry.
There are at least two more genera of the Daisy family that are closely related to the succulent Senecios. The first is the genus Solanecio, of which a spectacular member is the Canary Creeper Tree, Solanecio mannii, that occurs from Zimbabwe northwards. This plant has somewhat fleshy but also softly velvety leaves that can reach 40 cm (16 inches) in length, and daisy-like flowerheads in large terminal bunches. It becomes a tree of up to 7m (23 ft) in height. Other members of Solanecio occur in South Africa, where they are mainly climbers, not very succulent.
Another relative of Senecio is the genus Kleinia. In fact Kleinias are sometimes grouped under the genus Senecio. Kleinias are usually even more specialised towards surviving drought than the (other) Senecios are. Most Kleinias lose their leaves during growth, the function of photosynthesis then being taken over by the stems. The stems are succulent and diverse in shape. Kleinia longiflora has long stems streaked with lines, while Kleinia stapeliiformis has stems that become thickened in the middle, and with conspicuous ridges along them dividing the stem into a number of angles. The bases of the aborted leaves look like prickles along these ridges, making the plant appear somewhat like a prickly cactus or more relevantly here in South Africa, like an Euphorbia or like a Carrion Flower. Then there are species like Kleinia fulgens who do not lose their leaves, but these are thick and succulent ... though still flat and broad, unlike the finger-leaved Senecios. Kleinia often has attractive flowerheads ... the brush-like heads being large and bright orange or red in Kleinia fulgens, Kleinia stapeliiformis, and Kleinia galpinii, among others.
Kleinias are still very poorly known. For instance, there is a species of Kleinia growing close to where I live, in an open patch of land here amidst suburbs, that is used as a garbage dump. This species of Kleinia has not yet been found anywhere else and has not yet been officially described.
I have right now in my possession a plant that has not flowered yet, but I it believe to be a Kleinia longiflora. I am going to try and get some other Kleinias as well, especially the ones with the more attractive flowers.
As I learn more about Kleinias, I may put them into a separate entry of their own.
GARDENING WITH SENECIOS
The first very important thing is to use Senecios that are *INDIGENOUS TO YOUR COUNTRY AND/OR REGION*. The advice on gardening is NOT aimed at people in America or Europe! Only for people who live in South or Southern Africa. I am fanatical about gardening with indigenous plants ... plants that *belong* in the region where they are grown. So here in South Africa I concentrate on the South African Senecios, and even specifically, those that occur in the bushveld regions of the Transvaal which is where Pietersburg is situated. The best Senecios for this environment include Senecio barbertonicus, Senecio radicans, Senecio tamoides, and Senecio pleistocephalus. It's also not too bad to use some of the other South African Senecios, so long as you always bear in mind where their natural home is. For instance some are at home in the Western Cape where it rains in the Winter, not in the Summer. They need to have well-drained soil, and extra water in Winter. Also, Senecios from very dry regions should not be given extra water, and should receive full sun and well-drained soil. But it's best to use Senecios from the Summer Rainfall region, in the Summer Rainfall region.
Just note, PLEASE: it CAUSES ECOLOGICAL PROBLEMS when people import plants from foreign areas into their own! In South Africa for instance there are hundreds of plants from America, Europe, and especially South America, Asia and Australia, that have escaped from gardens and are now invading natural areas. These plants have no natural enemies here and soon crowd out the native plants. And this is causing big nature-conservation problems in many areas! And in exactly the same fashion, South African plants have escaped in countries like Australia where *they* are now the invaders and weeds that the people are having great difficulty eradicating. So DON'T, I repeat, DON'T, import South African plants into your local area if it's not South or Southern Africa! Those plants could too easily become an ecological problem and a threat to the plants that *really* belong where you are - your own country and region's indigenous plants. If you wanna promote plants, if you wanna make me happy, then learn about your own indigenous plants!!! But if you live in South or Southern Africa, you can use my practical advice.
The very largest and most rapidly growing Senecios, like the Canary Creepers and the Barberton Senecio, are best suited for *large* gardens. The big creepers should be given big trees into which to climb. These trees should of course also be indigenous, trees that will naturally occur in the same forests where the creepers come from. Also the trees should be big and strong and fast-growing so that they will not be overwhelmed by these vigorous creepers. Best choices for such trees include wild figs - the Common Wild Fig, Ficus burkei; the Broom Cluster Fig, Ficus sur; the Sycamore Fig, Ficus sycomorus; the Giant-leaved fig, Ficus lutea, and other big wild figs; the yellowwoods - especially the Outeniqua Yellowwood, Podocarpus falcatus; the Coast Coral Tree, Erythrina caffra; the Wild Peach, Kiggelaria africana; the White Stinkwood, Celtis africana; or any other fast-growing big South African forest tree. They could also work for some of the very big bushveld trees, especially those that grow along rivers, such as the Monkey Thorn, Acacia galpinii. Remember this is only for really large gardens. Structure your garden so that it looks like a natural kind of habitat, whether that be a mountain forest patch, a patch of 'koppie' woodland, or a patch of savannah woodland, or riverine forest. This will not only look the best, and the most natural, it will also draw the most species of birds.
The Barberton Senecio, because its natural habitat is rocky hills, will work very well in a rock garden, along with other succulent plants of similar habitats. It works especially well along other plants with finger-shaped leaves and stems, for instance the Rubber Euphorbia, Euphorbia tirucalli. It can be compatible with most other indigenous succulent plants as well, such as Plakkies (Crassula family), Vygies (Mesembryanthemum family), Euphorbias, Aloes and Carrion flowers. The Barberton Senecio should be allowed to become a big and spreading shrub receiving full sunshine ... it should not be overwhelmed by big, spreading and leafy trees. It would work best if it is among the biggest plants in its part of the garden, perhaps only with a few Rubber Euphorbias rising above, and with an underlayer of Plakkies, Vygies and other small succulents. Certainly it would be silly to plant just a single Barberton Senecio ... what would look best would be a group of at least five, spaced apart by inequal distances and not in straight lines!
The smaller succulent Senecios can work very well amongst other small succulents in forming underlayers for bigger succulents, and to provide interesting colours, shapes and textures. Smaller succulents are also more suited to smaller gardens.
Amidst the succulent plants there can also be some non-succulents that nevertheless come from the same kind of dry habitats in Nature.
Senecios are extremely easy to cultivate. They can be grown from cuttings ... even small cuttings would work. Cut them off the parent plant just before Spring, stick them in the ground, and they'll grow.
YET ANOTHER VERY IMPORTANT POINT: I really think that in gardening, and in trying to keep gardening in touch with ecology, we should not let our plants grow in our gardens, we shouldn't deliberately breed them, into forms that depart very much from their forms in nature. The plants in our gardens should in fact be plants that can survive in nature, and that are linked, interconnected, with their wild populations in nature. This is a core principle of my concept of Ecological Gardening.
I will soon try and start up a new website somewhere, and on this website I will put pictures - my own paintings, as well as photographs of plants that I have growing here at home, and photographs of plants taken in nature reserves, so that you can actually see what these plants that I'm talking about look like ... though I do think my descriptions are fairly thorough. I'll also put here links to pictures on the 'net.
Like I said, I will be rewriting, expanding and updating this entry as I learn more about the Senecios.
I don't care if nobody is interested in this ... this entry I wrote mainly for my own sake. But if somebody else is interested in this sort of thing it will make me happier.
Links (I'll activate them when I can):
Here you can see Senecios mentioned above, including Senecio articulatus, Senecio ficoides, Senecio rowleyanus, and Senecio (Kleinia) stapeliformis.