Learning key characteristics of just 19 families will, as William A. Weber, master of Colorado plants, points out in his Colorado Flora, Western Slope, assist in identifying over 75% of the plants in our area. The Western slope of the Colorado Rockies has over 2,100 species in 139 families, but Weber indicates that almost 1,600 species are in those 19 families.  The top six families are: Asteraceae (Sunflower) with 354 species, Poaceae (Grasses) 208, Fabaceae (Pea) 138, Cyperaceae (Sedges) 123, Brassicaceae (Mustards) 119, and Scrophulariaceae (Snapdragon) 99.  Note that four families (Asteraceae, Fabaceae, Brassicaceae, and Scrophulariaceae) have 700 out of the 2,100 plants. 

Remember also that you can learn family characteristics by learning species.  Learn what species a plant is and then see its similarities to another plant you find that same day and then notice in your field guide that they are in the same family.  Now you are learning the family characteristics not by memorizing those characteristics but by seeing the actual plants that possess those characteristics. 

How do we begin to identify a plant, to give a plant a name?

We work our way through books that lead us in a series of steps that place the plant in a large group (family) then a subdivision of the family (genus) and then a subdivision of the genus (species).  
This step by step approach is called "keying a plant".

There are many kinds of keys, ranging from those that work only by flower color, 
to those that start with flower color and then subdivide by family or by plant characteristics, 
to those that work only by plant characteristics.

Whatever key(s) one uses, if one wants to be sure to identify the plant correctly, the results should be confirmed with THE only complete key for all Colorado flora, 
William Weber's Colorado Flora, Eastern Slope  or  Western Slope, 2001 edition.  (A new edition is being worked on and should be available in 2009.)
Checking Weber for each plant will make you gradually more comfortable with a technical botanical key.    Eventually you may find yourself carrying only Weber on your field trips and consulting the other plant books primarily for their photographs and drawings.

Scientific names are based on Weber.

Scientific names are based on Weber.