9 Introduction to Plant Classification
Learning Objectives
- Recognize and describe patterns used to classify plants.
Classifying unknown plants as identical with or similar to plants within a particular taxonomic group involves observation and comparison. The ability to accurately distinguish and categorize the similarities and subtle differences among plant species relies on at least three interrelated skills: pattern recognition, description, and classification.
Pattern recognition includes awareness of visual indicators such as shape, size, habit, etc. as well as other sensory input such as smell, touch, sound, etc. Much pattern recognition depends upon our ability to describe what is perceived. Frequently, people don’t remember those things they can’t describe in words. In contrast, those things, which are related to other more familiar things, are more easily recalled: for example, “it feels like velvet,” “it smells of lemons,” or “it appears to be bigger than a breadbox”.
Descriptions allow people to identify and catalog those patterns. “Striped,” “spotted,” “rough” and “smooth” are simple descriptors. It is not difficult to remember such patterns. Other, more complex descriptors are needed for characterizing complex organisms. The “trick” is in recognizing the patterns that indicate important relationships. There is a significant amount of vocabulary involved in describing plants, and the student of plant identification must learn to apply both plant morphology (the study of shape) and the descriptive terminology.
Classification is an effective method for organizing data. People naturally classify things according to various categories. Based on their usefulness, some plants may be considered more desirable than others. For example, plants considered to be undesirable for health or economic reasons are often categorized as weeds. Additional categories used for plant classification include their utility (medicinal plants), cultural tolerances (house plants), growth form (trees), leaf shape (needle vs. broad leaves), their assumed evolutionary relationships and genetic sequences (phylogenetics), among others.
