Two interesting Euphorbias from the southern Great Karoo, part 1: E. braunsii

Last month my  friend George Hatting and I decided to spend a Sunday looking for plants in the Prince Albert area. We had both been there before and discovered some interesting plants.  After a nice drive over the spectacular Swartberg Pass, we arrived in Prince Albert and took a gravel road road from there heading east. Shortly after leaving town, we stopped at a place that looked promising and found a couple of beautiful small Euphorbia’s.  They clearly were plants of E. braunsii, which is well known from the area.

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This is how E. braunsii usually looks in the wild (well, normally without fruits, of course). Photo taken near Prince Albert on 10 Oct. 2012.

The peculiar thing was that they were in leaf, something I had never seen before and which is apparently a rare phenomenon. Digging into my literature I found no mention of the leaves, let alone a description or picture of them. The most likely explanation for this is that the leaves are short lived, as in the related (or maybe even identical) species E. rudis from Namaqualand and Namibia. Whatever is the case, I was quite chuffed to be there right on time to photograph the leaves, especially as they add an extra dimension to an already charming plant.

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The four pictures above were taken on 24 Febr. 2013

Next time we will look at a natural hybrid we discovered on this same trip.

Miniature succulents; masters of survival. Part 1

A few months ago I mentioned an article that I had written for “Veld & Flora” . Now that this has been published, I will share it with you here  in a slightly modified version.

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Succulent plants come in all shapes and sizes. Some of them, like baobabs and certain cacti, are enormous, able to store great quantities of water. At the other end of the scale, we find the results of a trend towards reduction that can be seen in several unrelated families such as Aizoaceae, Asphodelaceae, Asteraceae, Crassulaceae, Euphorbiaceae and Portulacaceae. These miniature succulents are both small and compact, not taller than a few centimeters, often little branched, without visible internodes and with more or less spherical leaves or stem(s). (In case you don’t know: an internode is the part of a stem between the points where leaves or branches develop).

Sometimes the trend involves neoteny. This is a situation in which plants or animals retain juvenile or embryonic characteristics throughout their life span, but nevertheless are able to reproduce. (A famous case in the animal kingdom is the Mexican axolotl).

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An interesting example in plants is the genus Oophytum, which only occurs on the Knersvlakte. It is a member of the Mitrophyllum group that only produces juvenile leaves. In effect, they are therefore perpetual seedlings.

Among succulent plant enthusiasts, miniatures are long-time favorites. This is hardly surprising, because even a small space can harbour a nice collection of them. There’s also an amazing abundance of shapes and colours, so that even without flowers there is always something to marvel over.
Last but not least, there’s great variety in their survival needs. In other words, both beginners and advanced growers will be able to find plants that fit their knowledge and ability. To grow some of these plants from seed to maturity is quite a feat, whereas others are much more amenable.
Even if you are not interested in keeping plants in captivity, there are many reasons for having a closer look at these dwarfs. In this article, we will focus on the way they cope with the challenges of their environment and make use of its opportunities.
Being small has both advantages and disadvantages, some of them evident, others much less so. Often the situation is rather complex. The solution for a problem may create a new problem, which in some cases is then (partly) remedied by another solution. Trying to understand this balancing act is an interesting exercise.
The accompanying pictures will hopefully convince you that these plants are not just interesting; they are also beautiful and visually stimulating.
The most obvious advantage of being small is that you need only little water, food and space to thrive. (Of course, the opposite is also true: when there is an abundance of these necessities, small succulents cannot compete with faster growing plants).
Because dwarf succulents can store only small amounts of water at a time, their storage organs have to be refilled at regular intervals, so the supply should be dependable. For that reason, the great majority of them occur in the Succulent Karoo, especially in Namaqualand with its predictable winter rainfall supplemented by even more reliable fog and dew.

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The hygroscopic fruit of this Argyroderma delaetii is still open early in the morning, as a result of the heavy nightly dew

The Succulent Karoo is not the only winter-rainfall desert in the world. Others are the southern Atacama Desert in Chile, the northwestern part of Baja California and the southern coast of Morocco. The first two especially, support a lot of succulents, but few if any of these are miniatures. In that sense, one could say that these little gems are a Southern African “invention”
The Succulent Karoo contains the richest concentration of succulents in the world. Whereas only about 140 species of stem succulents grow here, there are about 1700 species of leaf succulents, about 700 of which are small and compact. During the growing season, which is not just moist but also cool, these miniatures profit from the warmth of the soil.

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One of the few miniature succulents occurring outside the Succulent Karoo is this beautiful Frithia pulchra from Gauteng

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Not many stem succulents qualify as a miniature, but this Euphorbia pseudoglobosa from the Little Karoo certainly does

Small succulents are often restricted to places where water easily runs off, like gravel plains and quartz fields. Between and under rocks and stones, rainwater is often collected, providing moisture for small plants. In addition, dew and mist condenses on rocks and the moisture accumulates at their bases and in crevices. (Apart from water, this kind of habitat often also provides shade and protection from predators).

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This Conophytum pellucidum, photographed near Kamieskroon, looks quite happy with the little bit of extra water that collects at the foot of a rock slab

To be continued.

Under cover; ways and means of conserving water

When looking at all those beautiful and unusual forms, colours and textures in succulents, it is easy to think that all this is there  for our enjoyment.  I’m afraid  that is not the case; most of it is purely functional. For me, instead of  being disappointing, this fact adds to my pleasure and admiration.  What can be more likeable than things that are both useful and pleasing to the eye? In this post we will have a look at some of the contraptions that succulents use to conserve water.
The one thing that sets succulents apart from all other plants is their ability to store water that they can use during periods when there is no external supply.  Obviously it is not much use to store a lot of water if you do not have the means to conserve it as well. Managing the stored water sparingly, mainly  has to do with reducing transpiration.
The rate at which plants lose water by transpiration is influenced by a number of factors: size and form of the plant, temperature, humidity, intensity of sunlight, precipitation, wind speed, land slope etc.
On some days the temperature of the soil surface may rise as high as 75 degrees C, but a few centimetres higher up it will usually be much cooler  (up to 40 degrees less ). The two extremes will be separated by a layer of still air.
Comparable layers with gradients of humidity and temperature are found above plant surfaces; they have a great influence on transpiration. These layers are  disturbed or even destroyed by wind.  Because of this, many succulents have a cover of hairs, spines, etc. on the surfaces of their leaves or stems. This helps in producing and protecting these layers.  Such a cover  also gives a certain shade and helps to diminish exposure to strong radiation –especially when it is light in colour.  It has been found that tissue temperatures below spines of the cholla cactus (Opuntia bigelovii) can be reduced by as much as 11 degrees C.

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In this Anacampseros albidiflora, short hairs on the leaves and long bristles between them, cooperate to keep the plant cool

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Pelargonium barklyi is a tuberous plant. Although the leaves are short lived, it is apparently worthwhile to protect them with a cover of hairs     


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Haworthia arachnoidea  gets its name from the spiderweb like cover of hairs. This variety is called scabrispina because the hairs are rough and hard like spines

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In Senecio scaposus the leaves look like covered in felt

Many people think that spines are only there to protect the plants against browsing animals.  In line with what we have discussed here, I think that spines play a certain role in that respect too, but that it is not the only, or even the most important, one.

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 In cases like Othonna euphorbioides (above) and Euphorbia stellispina  -and in many other plants- the spines are actually hardened remains of inflorescences

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Leaf and stem surfaces are often thickened too, or coated with a layer of wax (Senecio stapeliiformis, on top) or cork (Othonna herrei)