THE ETERNAL PROBLEM OF TAXONOMY
From the Editor. Who of us fans has been indifferent to the names of our pets and to those changes repeatedly happening to these names? I think there is no such person. Also there is no single opinion of this problem. Some of us agree with regular changes of names or with transference of species into another genus, some of us do not. And this is quite normal. In the recommended article the author shares with us his thoughts on the problem. You may agree or argue with him. And this is also normal. Your opinions on the problem are welcome.
I had to look over a selection of statements on the problem of taxonomical system of the Cactaceae. Really, we force an open door again. To discuss the "eternal" problem of cacti taxonomy is quite an unproductive pastime I think. However to argue it coherently I had to write a thorough report. So I will confine myself to a number of thesis and I want to apologize beforehand for some confusion.
1. Botanists – cactologists make study of the vast and extremely complex group of plants belonging to the Cactaceae family. They appeal to various attributes trying to reveal relationships of various cacti groups hidden from us by history. The investigators put forward alternative versions of taxonomical system depending on the information received and their subjective viewpoints on evolutional and taxonomical value of these attributes.
2. Not only subjective viewpoints of investigators influence the systems offered but also the general tendency in taxonomy. It has been noticed that there is a cyclic change of periods when taxa are split or lumped. E.g. Curt Backeberg was a prominent representative of the "splitters", now there is a tendency to "lump" taxa and the leader of this trend is David Hunt*.
3. Appearance of new taxonomical systems invariably leads to changes of the names and elongation of the synonyms lists.
4. It wouldn't be correct to put a question about which system is "true". Any system reflects the amount of information and its evaluation by a researcher. In Backeberg's times the amount of information was different from that one of our days. Researchers should be blamed not for their conceptions but for their errors only. However to judge their errors one should have at least a comparable level of learning and competence.
5. Separation of any taxon higher than species in any system is relative and subjective as a rule. Nobody is going to challenge a statement that Rebutia and Sulcorebutia or Mammillaria and Dolichothele belong to the groups of cacti united on the basis of their origin. In practice it's on the whole of no importance whether to unite them into appropriate genera or to leave them independent. If I speak of Sulcorebutia steinbachii is it of importance to you whether I mean a cactus from genus Sulcorebutia or a cactus from subgenus Sulcorebutia in genus Rebutia?
6. Cacti fans are not indifferent to the innovations of systematists and ardently discuss them among themselves. However there's no sense to grieve about instability of modern system of the Cactaceae. Neither aesthetical nor collection value of our plants depends on the choice of its name to be written on the label. Also we can't be seriously worried about scientific controversy on genealogical relations between certain groups of cacti. Of real importance is the adequate mutual understanding between cacti fans: you must be sure that your colleague using a certain name means the same plant that you do.
7. Nobody would condemn you for using the name Neogomesia agavoides especially if you substantiate or stipulate for such usage. But it can't be tolerated if in one paragraph of your message you call a certain cactus Neogomesia and in another paragraph you call the same plant Ariocarpus. Or if in an article you speak of Ariocarpus agavoides and Roseocactus fissuratus at the same time. It's also incorrect to have such variant reading on the pages of one and the same publication, however this depends on the editor's qualification only. A serious damage to your reputation may arise not from the fact you use the name "Neogomesia" but from your ignorance of other existing views of these facts.
8. Using this or that system as a reference you shouldn't assess its correctness but only its practical convenience.
9. I prefer to use as a taxonimical basis the last revision of the system suggested by David Hunt (D.Hunt, 1999). This classification has undergone sharp criticism (especially from the serious amateur cacti growers) and is undoubtedly not irreproachable. But David Hunt is one of the best modern experts on cacti taxonomy; his work has been done under the aegis of trustworthy organizations and at last his system is a really full one reflecting taxonomical structure of the whole family down to every subspecies. Most important of all the Hunt's system gives a real chance to unify extremely intricate data on the family structure and the names of certain forms.
10. The Hunt system has the following inconvenience: the names of many popular forms used by cacti growers are ignored. Yet there's nobody to stop you from using these names. Any cacti fan would understand me if I speak about Rebutia minuscula grandiflora, and the name of the plant wouldn't contradict the Hunt's system.
11. All modern systems only indirectly reflect the real genetic relationships between cacti. However the real revolution in our views is not far off. Comparative molecular and genetic methods studies are being carried in biology on a larger scale. These studies give direct evidence of real links between cacti, and preliminary data may already be called sensational. The data show for example that Maihuenia is separated from other cacti on subfamily level, Blossfeldia as an evolutional group is comparable in rank with a subfamily, and Pfeifera can't be included into the genus Lepismium. All this is ever so interesting and intriguing, but really, can these objective changes influence the state of our collections?
12. There's no sense to "seriously" criticize the views of the researcher under the name of Doweld. As far as I know, the results of his original studies are not refuted. Moreover his staggering taxonomical deductions make no harm at all. Such publications contain paradox and stirring ideas and are necessary for the science to develop normally. At any rate they are a healthier phenomenon than no scientific publications at all in some organizations where they make researches in cacti taxonomy on official basis and keep large and unique collections of plants at the public expense.