A. Plants with needle-like leaves; non-flowering plant…..………Plant 1
A1. Plants with needle-like leaves, broad leaves, or stemless; flowering plant
B. Plants with white or yellow petals
C. Plants with white petals…………………………………Plant 2
C1. Plants with yellow petals……………………………..Plant 3
B1. Plants with no petals……………………………………………Plant 4
This is a clear key, and I could work my way through it pretty easily. I was a little unsure about how to work with clue C1, since none of the plants I saw had yellow petals. I was also unsure how it could be determined that Plant 1 was a non-flowering plant by looking at the photos alone.