To use any of these, you need to have a lot of information about the plant. A stem with leaves really helps but sometimes, especially with wildflowers and perennials, you need flowers and/or fruit or information about where the plant is growing.
I used almost all of these to identify a small flowering shrub I saw in Brown County State Park in southern Indiana. The Symonds books are great because you can use the plant part you have and match it to the photos in the book. Then, you can check that the other plant parts match. So, I looked for leaves that matched – alternate, simple, entire – and then checked each to see if the flowers matched.
I kept coming up with blueberry, which quite surprised me. Blueberries need acid soil and I wasn’t sure the soil in Brown County was acidic. We are very fortunate that Soil Surveys are now on-line (see http://websoilsurvey.nrcs.usda.gov/app/WebSoilSurvey.aspx). I was able to determine the exact soil type in which the plant was growing. Unfortunately, pH of the soil wasn’t listed, but I have a list of all soil types in Indiana that told me that the soil in that area of Brown County was indeed acidic.
But which blueberry was it? Symonds book suggested it was Vaccinium stamineum or deerberry. The flowers are flared open unlike other blueberries and there are small leaves close to the flowers. I was fortunate to find this plant on the Missouri Plants webpage (an excellent resource) and confirmed it with a colleague at Purdue.
So, using a good reference which gave details of both leaves and flowers, double-checking site conditions, and verifying with experts led me to the ID. Believe it or not, this is an example of a do-able ID. When the plant is not in any of your references or when you have to resort to looking through photos to see if you can find a match, then you’re in trouble!
