monosepalous
Mon`o*sep"al*ous, a. Etym: [Mono- + sepal: cf. F. monosépale.] (Bot.) Defn: Having only one sepal, or the calyx in one piece or composed of the sepals united into one piece; gamosepalous. Note: The most recent writers restrict this term to flowers having a solarity sepal, and use gamosepalous for a calyx formed by several sepals combined into one piece. Cf. Monopetalous.