perianth noun. ['pɛrɪanƟ] Orig. in Latin form perianthium [pɛrɪ'anƟɪǝm]. E18.
[French périanthe from mod. Latin perianthium, formed as PERI- + Greek anthos flower, after pericarpium PERICARP.]
Botany.
1. A calyx; (in plants of the composite family) the involucre. Only in 18.

2. The protective outer whorl(s) of a flower, esp. one in which corolla and calyx are not differentiated. E19.

3. The fused uppermost perichaetial bracts surrounding the calyptra of a liverwort. M19.

Comb.:
perianth segment one of the distinct leaves forming a perianth, esp. when they are not differentiated into petals and sepals.

[TahlilGaran] English Dictionary ▲