If you are logical, you won't find a better answer out there. It is coming from Plante-à-Genêt. Plante-à-Genêt are French words. (I know my mother tongue is French) I am posting this because there are people speaking whatever about this and it irritates me because it is coming straight from elucubrations (yes, it's an English word too, I verified) from their ignorance, just pretending to know about this actually know MAJUSCULE zero, NIET.
Here is where Plantagenêt comes from. During a battle, Geoffrey of Anjou lost his badge and took the yellow spring of a common broom plant to replace it, thus the infamous Plante-à-Genêt. (and not Plante Genest like others pretend, no no no) Even Wikipedia agrees with me and I quote: "Geoffrey of Anjou, perhaps received the nickname (much later used for the royal dynasty that resulted from this marriage) from the yellow sprig of broom". To conclude, the house's founder, Geoffrey of Anjou, often used to wear it in his hat.
Comprende? If not, continue to do you. Speak from your pompous ignorance.
