The Blackberry - la Ronce
I have yet to fathom the derivation of the French word for this species. The Larousse dictionary would have us believe that it comes from the same root as 'rumex' and suggests that the word meant 'thorn'. Pliny the Roman, used the word 'rumex' for the sorrel, which has no spines at all! Why did the Gauls not call the bramble 'rubus', or 'vepres' which are two good Latin words for it? I have a feeling that the origin is the Latin 'runco' - to weed or 'runcatio' -a weed. The ancients were no doubt as plagued by the ronces as I am and probably spent many hours weeding them out! The name for the fruit, 'mûre', is also the fruit of the mulberry tree. This also strikes me as odd. Although the shape is similar it is impossible to confuse them.
The number of species of blackberry is enormous. More than 400 species are listed in Europe. These are grouped around seventy five reasonably distinctive forms. The raspberry is one of them. If you start looking you will find some with angular stems, others circular. Some have strong thorns, some weak spines. Some stems are glandular, others are not. The flowers and fruits vary in size and formation. The leaves sometimes have five leaflets, sometimes three, or seven. Some leaves are white beneath with a cottony growth. All this variation comes about because they have an unusual reproduction. Most often the seeds develop without a pollination process, and so the offspring are identical to the parent. Besides that, the natural layering of the stem tips ensures thickets or woods full of identical brambles. But occasionally crossing and hybridisation occurs and then a new distinct form arises! And from that you can philosophically argue for hours on 'what is a species?'
One does so wish that something would control their growth. The goats do quite well with the young shoots, but the effect is temporary. There are some fungi which attack the leaves. On the under side of the leaves you often see small rust or black pustules (Phragmidium rust). They appear on the upper side as crimson spots as in the photo. They hardly affect the growth. Minute species of moth caterpillars burrow between the upper and lower skins of the leaves. The right hand leaf shows two of these. They also scarcely affect the leaf's performance. The ronce is indeed an encumbrance.
You can imagine the Roman slave master ordering the gaulish peasant to 'purga illae runcationes' .