What is a plant whose flowers may be dried without losing their form or color, as the pearly everlasting (Anaphalis margaritacea), the immortelle of the French, the cudweeds, etc called?

everlasting — (Bot.) A plant whose flowers may be dried without losing their form or color, as the pearly everlasting (Anaphalis margaritacea), the immortelle of the French, the cudweeds, etc. (Webster's 1913.)