Tolerating the devil in our midst

I was walking along Farmersfield Road right outside Farmersfield Village and I saw an alarming number of devils. No kidding!

There are an alarming number of devils visible in this picture.

Well, actually, what I saw was duiweltjiedorings, devil thorns, Tribulus terrestrial. 

I pulled out some 30 individuals, but that is but a small fraction of the number of individuals about. If each person that sees this, or any other aggressively invasive species, pulls out and destroys 30 individuals, preventing them from seeding, we would make a significant impact on reducing its spread. For any individual that we tolerate, we will enable 'one year seeding, seven years weeding'.

The green dots show some of the localities where duiweltjiedoring has been observed in Southern Africa between 1830 and 2012

The duiweltjiedoring is native to warm temperate and tropical regions in southern Eurasia and Africa. This is a species that survives in dry conditions and is very abundant in our Fairest Cape. It is evidently not an alien to South Africa, but it certainly can be a noxious weed.

The survival of any plant species depends on various factors that include;

• the dispersal of the seed;
• then the germination of the seed;
• then its survival beyond seedling stage;
• then reaching flowering stage;
• then being pollinated;
• then developing a viable seed;
• and the dispersal of the next generation of seed. 

Along the way from germination to seeding, there are impacts such as;

• grazing/eradication/harvesting;
• trampling;
• insufficient subsequent rainfall to enable the roots to penetrate deep enough to survive through future dry periods to reach flowering and fruiting stages;
• fire;
• unsuitable (e.g. rocky or hard) substrate;
• inadequate pollination;
• and various other adverse effects.

In addition to these impacts, success is determined by:

• the numbers of seeds produced;
• the proportion of those seeds that develop fully;
• the rate of dispersal;
• the distance of dispersal;
• the germination rate (the percentage of seeds that germinate);
• and other statistical factors affect the successful seeding, germination, and survival of the seed.

Now, for the readers with critical minds, I had a quick look at some of these variables in this group of plants. I looked at 23 plants within and area of maybe 0.5 square metre (about 40 cm x 40 cm, about 2 square feet). There were about 6 that looked like small seedlings of which 3 had no flowers or seeds, but others had up to 14 flowers or seeds. The one plant with the most seeds had 43 flowers/fruits, with 5 fruits per flower, giving about 215 seeds on that one plant since one flower produces 5 fruits. The average was 66.5 seeds per plant, a standard deviation of 54.6 (meaning that 90% of plants in a population would have between 12 and 121 seeds), and a median of 50. There were about 50 to 200 seeds left on the ground under where I removed these plants. This brings to mind the parable of the sower with some seeds that fell on good ground brought forth hundredfold, some sixtyfold, some thirtyfold while others did not even germinate, and some germinated but then dried up in the sun.

A large individual

One individual can stretch over a long distance.

The flower produces a fruit with five separate seeds. 

A seedling with no visible fruit.

The devil thorn/duiweltjiedoring evidently has several uses in traditional medicinal. It can also be used in cooking and the roots and shoots can be eaten. But I suggest that the plant be grown under controlled conditions rather than it spreading out-of-control on our sidewalks where it hurts us if we step on or touch the bur, or where it can so easily puncture a bicycle tyre, or any of the other unpleasant effects of it growing in our neighbourhoods.

As it is said, the easiest way for evil to succeed is for good people to do nothing. 

Let us be one of those who does something. Let us not tolerate the devil [thorn], anything devilish, including undesirable invasive species, or any evils in our environment when we are able to do something to remove them. 

As the milkman Reb Tevye in Fiddler on the Roof often said, 'On the other hand', just as undesirable seeds are - well, undesirable - so we can sow good seeds and reap good - desirable - harvests. Let us sow seeds of charity, love, inclusiveness, kindness, and other desirable fruits. It is good to bear in mind that even undesirable things about us can have good - the duiweltjiedoring has medicinal values, the invasive gumtrees support bees that are essential for most of our agricultural crops. It is by experiencing the bitter that we can appreciate the sweet, the dark helps us to appreciate the light, and so forth. But let us be sweet and light rather than being bitter or dark - there are more than enough others around us that will provide the bitter and dark.

Let us be part of the solution and not part of the problem in any situations where we can make a big difference by doing small and simple things. I am far from perfect, but I am working on it...