What is in the group
Chamomile, lavender, rose, elderflower, chrysanthemum, osmanthus, butterfly pea and hibiscus — though hibiscus is the odd one, because the part used is the calyx rather than the petal. Most are dried whole and most are recognisable in the packet, which is unusual among botanicals.
Why they are the most fragile
Flower aromas are carried by volatile compounds that heat drives off, and a flower has very little mass to hold them. This is the group where drying temperature matters most and where the difference between careful and careless production is most obvious to a drinker.
Strength varies enormously
Chamomile is mild and a heaped spoonful is reasonable. Lavender is so strong that a pinch is correct and a spoonful is a mistake. Osmanthus dominates anything it is blended with. Treating the group as uniform is the commonest error with flowers.
Whole flowers are a real quality signal
In this group, and not in every group, appearance tells you something. Intact heads that open in hot water were dried carefully. Broken petals and dust are the same plant handled badly, and they extract faster and more bitterly.
Scenting versus infusing
Several of these — osmanthus, rose, jasmine — are used more often to scent tea than to be drunk alone, by layering with finished leaf and then removing the flower. That is a different process from blending dried flowers into a packet, and the results are not comparable.