The Collaborative International Dictionary
Acalycine
Acalycine \A*cal"y*cine\, Acalysinous \Ac`a*lys`i*nous\, a. [Gr. 'a priv. + ? calyx.] (Bot.) Without a calyx, or outer floral envelope.
Wiktionary
acalycine
a. (context botany English) Without a calyx, or outer floral envelope.