Pustules on the leaves of Lysimachia, Ajuga, etc., are due to the parasitic Alga Phyllobium.

Bracts sometimes do not differ from the ordinary leaves, as in Veronica hederifolia, Vinca, Anagallis and Ajuga.

The English name "bugle" is also given to a common labiate plant, the Ajuga reptans, not to be confused with the "Bugloss" or Anchusa officinalis.