Would you like some instances?
"According to her, the plantain cures anyone who has eaten or drunk poison, and the pimpernel has the same virtue when hung round the neck.
Myrrh must be warmed against the body till it is quite soft, and then it nullifies the wizard's malignant arts, delivers the mind from phantoms, and is an antidote to philtres.

It also puts to flight all lascivious dreaming, if worn on the breast or the stomach; only, as it eliminates every carnal suggestion it depresses the spirit and makes it 'arid'; and for this reason, adds the saint, it should never be eaten but under great necessity.
"It is true that as a remedy against the dejection caused by myrrh we may apply the 'hymelsloszel' (Himmelschluessel), which is--or appears to be--_Primula officinalis_, the cowslip, whose bunches of fragrant yellow blossoms are to be seen in moist woods and meadows.

This plant is 'warm,' and imbibes its qualities from the light.

Hence it can drive away melancholy, which, says St.Hildegarde, spoils men's good manners, making them utter speech contrary to God, on hearing which words the spirits of the air gather about him who has spoken them, and finally drive him mad.
"I may also tell you of the mandragora, a plant 'warm and watery,' that may symbolize the human being it resembles; and it is more susceptible than all other plants to the suggestion of the devil; but I would rather quote a recipe that you might perhaps think useful.
"Here is our Abbess's prescription _a propos_ to the iris or lily: Take the tip of the root, bruise it in rancid fat, heat this ointment and rub it on any who are afflicted with red or white leprosy, and they will soon be healed.
"But enough of these old-world recipes and counter-charms; we will study the symbolism of plants.
"Flowers in general are emblematic of what is good.

According to Durand of Mende, both flowers and trees represent good works, of which the virtues are the roots; according to Honorius, the hermit, green herbs are for wisdom; those in flower are for progress; those in fruit are the perfect souls; finally, we are told by old treatises on symbolical theology that all plants embody the allegory of the Resurrection, while the idea of eternity attaches more particularly to the vine, the cedar and the palm." "And you may add," the Abbe Gevresin put in, "that in the Psalms the palm figures the righteous man, while according to the interpretation of Gregory the Great its rugged bark and the golden strings of dates are emblematical of the wood of the Cross, hard to the touch, but bearing fruit that is sweet to those who are worthy to taste them." "Well," said Durtal, "but supposing that Madame Bavoil should wish to plant a liturgical garden, what should she select for it?
"Can we, to begin with, compose a dictionary of plants representing the capital sins and their antithetical virtues, sketch a basis of operations, and pick out by certain rules the materials at the command of the mystic gardener ?" "I do not know," said the Abbe Plomb.