Culpeper places wormwood under Mars, and reads its extreme bitterness as the martial signature. That much is ordinary. What is not ordinary is the entry itself.
The wormwood article in the Complete Herbal is the longest and by some distance the oddest in the book. Culpeper abandons the format he uses everywhere else (description, place, time, government and virtues), and writes several pages of first-person argument about martial sympathy, addressed partly to the reader and partly to his critics, ranging over the wars of the planets, the doctrine of sympathy and antipathy, and a good deal of self-defence. It reads as a manifesto that happens to have been filed under a herb.
This matters for how the book should be used. Culpeper was not compiling a neutral reference. He was a radical who published in English, deliberately, to break the Latin monopoly of the College of Physicians, and the Complete Herbal is a polemical work as well as a practical one. The planetary rulerships in it are his own systematisation, applied consistently but from a theory he was arguing for rather than reporting.
The consequence is that a phrase like Culpeper assigns this herb to Mars means something narrower than it sounds. It means one seventeenth-century English astrologer-physician placed it there, in a scheme he was actively promoting, for reasons he sets out and which can be examined. It does not mean the attribution is traditional, and it certainly does not mean it is ancient.