Floral envelope and Plant organ

Floral envelope noun - Collective term for the outer parts of a flower consisting of the calyx and corolla and enclosing the stamens and pistils.

Plant organ and floral envelope are semantically related. In some cases you can use "Plant organ" instead a noun phrase "Floral envelope".

Plant organ noun - A functional and structural unit of a plant or fungus.

Floral envelope and plant organ are semantically related. Sometimes you can replace phrase "Floral envelope" with "Plant organ", this phrases are similar.