in botany, "envelope of a flower," 1706, from French périanthe, from Modern Latin perianthium (17c.), literally "that which is round the flower," from Greek peri "around, about" (see peri-) + Greek anthos "flower" (see anther). Related: Perianthal.
word-forming element in words of Greek origin or formation meaning "around, about, enclosing," from Greek peri (prep.) "around, about, beyond," cognate with Sanskrit pari "around, about, through," Latin per, from PIE root *per- (1) "forward," hence "in front of, before, first, chief, toward, near, around, against." Equivalent in sense to Latin circum-.
1550s, "medical extract of flowers," from French anthère or Modern Latin anthera "a medicine extracted from a flower," from Greek anthera, fem. of antheros "flowery, blooming," from anthos "flower," from PIE root *andh- "to bloom" (source also of Sanskrit andhas "herb," Armenian and "field," Middle Irish ainder "young girl," Welsh anner "young cow"). The botanical sense of "polliniferous part of a stamen" attested by 1791.
<a href="https://www.etymonline.com/word/perianth">Etymology of perianth by etymonline</a>
Harper, D. (n.d.). Etymology of perianth. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/perianth