a·cyc·lic 
(ā-sĭklĭk, ā-sīklĭk)
(ā-sĭklĭk, ā-sīklĭk)adj.
1. Botany Not cyclic. Used especially of flowers whose parts are arranged in spirals rather than in whorls, as in magnolias.
2. Chemistry Having an open-chain molecular structure rather than a ring-shaped structure.