During this lab you will become familiar with how to use a dichotomous key as well as the nomenclature you need to know to understand it. In addition, we will dive into smartphone apps and how these help us in identifying plants...but their results are often flawed and should be viewed as helpful but not authoritative! As well as dichotomous keys we will also be introduced to multi-access keys that have become possible with the advent of computers. The point of this lab is not to miraculously be able to identify all plants, but to better know and practice the process of plant identification. We will be continuing to focus on our 8 major families: Mint - Lamiaceae; Mustard - Brassicaceae; Parsley - Apiaceae; Pea - Fabaceae; Lily - Liliaceae; Grass - Poaceae; Rose - Rosaceae; Aster - Asteraceae.
“Keying out” is a daunting but essential skill for anyone interested in Botany. To do this you need to know how Botanical (Dichotomous) Keys work, how to find your way around them, and their use and application – and their limitations. Additionally, multi-access keys are a new innovation along with picture-based smartphone apps as well as the versatile Google reverse image search or the new Google Lens.
There is a whole lot of plant jargon connected to plant physiology that we will not get into as part of this lab. Some of this jargon you will learn throughout the course while many terms will be left for your to research on your own as you go about using plant ID guides. There are three parts of this exercise...
Part I: Creating your own dichotomous key: For this activity you will use the same plants that you found and identified to family as part of your walk for the previous lab. This may seem trivial, but this exercise is designed to both (i) continue to work on getting familiar with our 8 major plant families and (ii) understand the basics behind how dichotomous keys are built and how they function. Here is an example of a dichotomous key of Asteraceae from Wisconsin (need to scroll down to page 1). This shows you how complex dichotomous keys can get - but we are not getting too complex for this lab! To build your dichotomous key assemble your 8 plants and determine which key characteristics set them apart. For example "green leaves" would not be very effective at distinguishing these 8 plants but "alternate leaves" starts to get you somewhere. Since we are still at an early stage in our botanical knowledge feel free to use jargon as much as you like but also feel free to use descriptive terms. At this point in our semester it is not as important that you know all the jargon as much as that you know how a dichotomous key is built and used for plant identification. Your first step is to build a table detailing your 8 plants and the distinguishing characteristics you have chosen to build your key. Remember these 8 plants are from 8 VERY different families so it should not be difficult to find traits that differentiate them. Again you are keying out to family....NOT species. Your second step is to type out your dichotomous key directly on your lab webpage (text only as is standard for keys). These two videos describe the process in sequence:
How to make a dichotomous key - Part I
How to make a dichotomous key - Part II
Part II: Going deeper with your family IDs by using apps & Google
Dichotomous keys are a common, but not the only tool we have to identify plants. Nowadays we have an entire internet full of plant images and sophisticated algorithms to search your picture against this boggling world wide database. Though it should also be mentioned that these apps are not where they need to be yet and any answer they give you should be tested against some other source. Throughout this course you will be building up your plant knowledge so that by the end of the semester you will feel much more capable of truth-checking these apps yourself!
There are a number of apps that work on smartphones for you to choose from. A couple of my favorites are Picture This and PlantNet. Lots of folks also like iNaturalist. I am actually starting to also use Google Lens which hooks directly into Google's massive database of images. It is basically an instant Google reverse image search for your smartphone.
All you are doing for this part of the lab is experimenting with at least 1 app-based tool for identifying plants. You will then write a short reflection on this experience on your lab webpage.
Part III: Test Driving a Multi-Access key and comparing it to the dichotomous key approach
Now that we have computers we have multi-access keys. Some recent studies have found that these multi-access keys are faster and more intuitive than dichotomous keys. Instead of looking at one trait at a time, multi-access key users are able to list all the traits they see in their specimen and then ask the key to search through all candidate plants in its database to ID your specimen. It is a new powerful approach that may now be as portable as a field guide thanks to smartphones. For this lab you just simply need to test drive one of these apps and form an opinion on the experience. Feel free to use one of your plants of just play around with the interface. Here are some options for online keys to use:
My Recommendation: GO BOTANY by Native Plant Trust --- With this online multi-access key you are asked to first narrow down which group of plants you are looking at by answering a few simple questions (with pictures as support). Once you have answered these it takes you to a screen with a bunch of candidates. There are additional questions to answer in the left margin (you don't need to answer all of them) - again you are walked through these options with pictures and drawings. Once finished you are presented with the remaining candidates. This is made for New England but many of these species are also here in Indiana.
Other keys are as follows:
Embedded Google Sheets table of your 8 plants and distinguishing traits [15pts]
Resulting dichotomous key typed directly into your website (don't embed anything) [30pts]
One paragraph describing what you learned from the process of constructing a dichotomous key [5pts]
One paragraph reflecting on your interaction with your app(s) and their utility (and pitfalls) when it comes to plant identification. Please also type out your species IDs - it doesn't matter if they are correct or not.[5pts]
One paragraph reflecting on your interaction with your multi-access key(s) and their utility (and pitfalls) when it comes to plant identification - especially when compared to the dichotomous key approach [5pts]
Below are some other videos and links you may find useful with thinking about plant ID or when sorting through the nomenclature and terms used in keys. These are not required viewing/reading but may prove useful.
Leaf Shape - ovate; lance; elliptical; egg; linear; obovate; compound, palmate