How are angiosperms used

On the systematics of flowering plants

The bedecktsamer (Angiospermae) as flowering plants in the narrower sense are the most species-rich plant group and at the same time also the youngest development line of the plants. While their biodiversity makes classification difficult, their relatively contemporary evolutionary development should facilitate the elucidation of their phylogenetic and kinship relationships. But the origins of angiosperms as a whole as well as their lines of development are in the dark.

Systematics as taxonomy and phylogeny

Systematic botany should be easy to understand; but these have not been the identification keys since Otto Schmeil for a long time.

The authorities of botany loved to cover the basics of plant life with such a multitude of German and Latin technical terms that the meaning of their statements disappeared in a dark hole. Today you also have to grapple with perhaps even more extensive English technical terminology. The inclusion of a myriad of chemical compounds and genetic abbreviations that are considered important also makes taxonomic botany more and more incomprehensible.

The greatest problem, however, is the knowledge of the algorithmic data processing methods that are used to prove phylogenetic relationships.

From an objective point of view, taxa are perhaps only human attempts at definition and description; however, it can be assumed that they are based on a recognizable biological order (Melchior 1954).

I can do such a thing in that cladistic system of the "Angiosperm Phylogeny Group"that was published on the Internet. After all, the academic treatment of the biological order has been made available to the entire public and has been appreciated in great completeness and detail.

All traditional attempts at the systematic classification of the plant world were based on external characteristics or similarities; today's classification relies on statistical and genetic similarities.

Carl von Linné set up his system on the basis of the number of certain flower organs.
Since the 1950s, John Hutchinson developed a botanically and practically much more competent system, which was divided into two lines of development, each mainly consisting of woody plants and herbaceous plants.

Both models can be viewed as artificial systems, although they are based on natural features. However, Hutchinson also relied on evolutionary considerations and was perhaps even right.

Many plant systems and taxa are criticized for the fact that only external features are used that do not reflect the natural relationship; this is consequently pressed into an artificial system.

To find out the natural origins of the species living today, however, one would have to go back to distant geological epochs. And a natural phylogenetic system including paleontological, genetic, evolutionary and ecological data is subject to constant change - not only in such an enormous geological time frame, but also in the relatively short term. Also because of frequently changing conflicting academic views ...

The general and scientific recognition of a species can only be made on the basis of the description of its external characteristics. Since the 19th century this has also been done taking into account the anatomical properties of herbarium material (Wagenitz 1986).
The same requirements should of course also be met by the superordinate taxa, which form the actual plant systematic classification, in that species are grouped based on their similarity and relationship.

The separated flower petals in Schmeil's "Pflanzenkunde", 150th edition, 1931.

Now that an extensive inventory had been drawn up on the basis of the manifested external form, one began to question these taxa on the basis of their chemical constituents and genetic makeup.

It should not go unmentioned that the methods of systematics have always required extremely complex working methods; the same have meanwhile also been achieved by the industrial scale of information technology.

New methods

In the 1960s, Willi Hennig (1913-1976) suggested cladistics or phylogenetic systematics - a method of graphically depicting complex developmental relationships in so-called cladograms or branching diagrams.
A dispute between evolutionary taxonomy and the cladists is said to have arisen from the start - among other things because of the classification of fossil records in cladistics (Gamlin / Vines 1986).

In the current taxation experiments based on chemo- and molecular-analytical, but above all information-technical-statistical investigations, not only the higher-level taxa are largely destroyed, but also the known systems of characteristics and description. The explanations for the new plant systematic groupings are rather poor and in incomprehensible technical jargon. As a result, the phylogenetic systematics or the relationship of the plants becomes less and less comprehensible - neither recognizable with the senses nor conceptually or mentally comprehensible.

The first system of this type is the plant systematics of the "Angiosperm Phylogeny Group (APG)", which is accessible to everyone online (www.mobot.org/MOBOT/research/APweb), but is a very thankless read.

The most drastic difference between the new cladistic system of the APG and the old systems is the task of the formal taxa above the order.
In species-rich groups of organisms such as flowering plants, however, higher-level taxa perform a particular function, as they can provide a better overview than dichotomous cladograms.

Another feature of the new system that makes it look very unfinished is the segregation of many families etc. as not belonging to the higher clades and taxa. The characteristics defining a cladus are extremely opaque.

There have always been groups of plants that you didn't know where to classify (as an example among many, the Salicales); these were put together with similar to not directly related (polyphyletic) groups. In a new system of plants, this should evidently be avoided at all costs; therefore, a number of taxa such as the Ceratophyllaceae apart, whose real position one is not clear about.

Viewed realistically, this can also mean that there can no longer be any real relationship between the diverse plant types above certain taxonomic categories. But this is a point of view that again suggests polyphyletic groupings.

In the new systems, the species, genera and plant families worked out by many generations of botanists have evidently remained largely untouched by modern analysis methods. From this one can derive the hope that the external appearance of the plant beyond its molecular structure and digital data analysis can lead to tangible phylogenetic findings.

I do not think that it is the right method to compress extremely complex biological and biochemical conditions into an extremely simple dichotomous representation method (cladistics). The plant world is reduced to statistical functions and chemo-analytical reactions, its position in reality is neglected. - In the past, however, it was anatomical and embryological subtleties that obscured the need for practical botany.

Parataxonomy

For human needs, other systems of taxonomy are certainly more sensible than those of kinship:

  • Utility functions
  • Identifiability
  • geographical distribution
  • ecological adjustments
  • biological and physiological functionality

Such classifications for practical use are given by Spichiger et al. 2004 called 'parataxonomy'.

P. F. Stevens from APweb (Stevens 2012) remarks that a taxon (especially among the higher-level taxa) could be defined by general consensus, but its phylogenetic position exists (or does not exist) independently of human consensus ...

In the past, systematic botany was equated with taxonomy. Then the classification of the external appearance of the plants was made even more difficult by the scientific requirement to also show the evolutionary relationships. - For what purpose?