Dog Daisy, Dog Violet & Dog Rose

Since I know you won't sleep until you know the answer:-

‘Dog' refers to its lack of scent, as opposed to ‘sweet' violet. Dog, like horse, is a common English prefix for distinguishing an inferior species from its superior relative. https://www.plantlife.org.uk/uk/discover...let-common

Although, as Scarlet says, its not quite true for the Dog Rose https://www.plantlife.org.uk/uk/discover...s/dog-rose

As for the Dog Daisy/Oxeye daisy/ Horse Daisy and more
Before the 16th century it was more commonly known as the 'Moon Daisy' or 'Dog Daisy'. Also called Horse daisy, Moonpenny and Marguerite. References to the moon derive from the fact that this bright flower can seem to glow in the fields on midsummer evenings. https://www.plantlife.org.uk/uk/discover...xeye-daisy

Next question, if "Dog" and "Horse" mean unscented, how many plants can you think of with "Horse" in their name?

The Dog Daisy is called Horse Daisy - that's one!
Horse Mint I know.
Any others?

Horse chestnut?
Horsetail?

I've no idea whether Horse Chestnut flowers are scented - I'm not tall enough to sniff one. However..........

The leaf stalks leave a scar on the twig when they fall, which resembles an inverted horse shoe with nail holes. This association with horses could explain why conkers used to be ground up and fed to horses to relieve them of coughs, and could be the origin of the tree's name. https://www.woodlandtrust.org.uk/trees-w...-chestnut/

I'm learning so much tonight.

Horse mushroom

Horseradish!

Horseradish!

The word horseradish is attested in English from the 1590s. It combines the word horse (formerly used in a figurative sense to mean strong or coarse) and the word radish.
https://en.wikipedia.org/wiki/Horseradish#Description

Well, well - no scent. Didn’t know that.
I thought all violets were scented, shows how much I know.