One could say the dicotyledonae are less primitive than monocotyledonae, but that might be jumping the gun on the final decision. Dicots are a great deal more chemically complex than monocots in the long run. But monocots benefit by being more selective in their production of highly selective toxins. By not wasting energy on the production of numerous complex, chemical paths, they more likely to be able to develop specific agents when they need them in specific environmental settings. The best example of this is the orchid, which produces certain compounds related to its symbiotic relationships with its pollinators. This doesn’t mean dicots haven’t developed some of the same symbiotic relationships. Like their ability to produce antiherbivore compounds, so too can they produce chemicals that attract animals. Not only are these the aromatics released into the air or the flavonoids found in the petals, these are also the basic terpene products that insects extract from plants and use to produce their own mating hormones, or the nutrients ants need to build their colony.
When we look at dicots and their chemical production, the following rules relate to the dicots and their chemical synthesis pathways.
- The chemotaxonomy of dicots groups diverge as much if not more than their physical taxonomy
- The parallel and/or divergent evolution nature of plants hold true in the chemical features as much as in the physical features, but with the chemical features may do so due to completely different phytochemical production routes. As an example two completely unrelated plants can both produce nicotine for the same reason, along very different pathways.
- Dicots following the basic rules of increasingly complex chemical production (defined elsewhere) in large numbers and at various levels of interaction and complexity; this is due in part to their much broader numbers and varieties of plant Genus species members, thereby increasing the likelihood that complexity will ultimately ensue.
- The variety and numbers of products of a chemical pathway or series of pathways in plant is related to the numbers and complexity of taxa at all levels of breakdown and classification. (There are more branches, with more possible routes, and therefore there is much more chemical diversity)
In the taxonomic system used here, both dicots and monocots have six subclasses. The diversification that takes place occurs below the subclass level. Without looking at the numbers of these sub-subclass groupings, the following is the relationship between the major plant chemical groups for the dicots:
[Note: Each Subclass has its own color assigned to the lines. The Caryophyllidae is indicated by the single purple line, not a branch linked to Asteridae; all of the Asteridae is the yellow line.]
The following is the chart for all plants based on the same subgrouping and color key used to make the barcharts above (and for the most part, the pie charts).
The kinds of questions the above chart might answer are:
- Where is the Subclass with the greatest percentage of its genera consisting of wood and fiber sources?
- food and flavorant sources?
- the largest percentage of toxic plants?
- potential aromatics?
- potential dye sources?
- what is the single most sacrificed ethnobotanical use sacrificed for an increase in the percentage of all other ethnobotanical uses as implied by the chemicals?
Brian Altonen, MPH, MS 
