Lucid keys are fault-tolerant – they can forgive commonly made mistakes over features that are often misinterpreted.
For example, the flower of an arum lily (Zantedeschia aethiopica) is not the white structure arrowed (Fig 1). In fact, the arrow points to a white petal-like bract (called a spathe) and numerous flowers are separated by gender along the yellow elongated flower spike (the inflorescence) (Fig 2).
|Figure 1. The arrow points to a white petal-like bract called a spathe. Image - Trevor James||Figure 2. Flowers are separated by gender along the inflorescence. Image - Trevor James|
If you made this common misinterpretation in the Weeds Key, and as a result incorrectly scored ‘Flower Type’, ‘Flower Structure’, ‘Flower Size’, or ‘Inflorescence Type’, arum lily would not be discarded in the identification process.