zed·o·a·ry (zed´ō ãr´ē) n. -ries. an herb native to southeast Asia (Curcuma zedoaria (Bergius) Roscoe, of the Zingiberaceae), bearing striking whitish-green leaves with a purple midrib, and an aromatic rhizome used to a certain extent in folk medicine. [ME < Med.L zedoarium < Persian zadwār]

zel·ko·va (dzel kō´vä) n. any of several species of the genus Zelkova Spach (of the Ulmaceae), shrubs or trees native to Transcaucasia, and strongly resembling elms. It is often used as an ornamental tree, or as a bonsai or for its sturdy wood. There are two disjunct species on the islands of Crete and Sicily. [< NL < Kartvelian, cf. Georgian dzelkva ძელქვა < dzel ძელ bar + kva ქვა rock]

zos·te·ro·phyll (zos´tə rō fil´) n. a fossil plant form whose members essentially lack leaves of any kind, but otherwise are closely-related to the clubmosses, and may possibly be considered members of the lycopodal alliance. They tend to exhibit dichotomous branching, lateral reniform sporangia which dehisce laterally, and stems which are either smooth or exhibiting numerous spiny enations (perhaps incipient microphylls?). They were cosmopolitan in the Silurian and Devonian geological periods. [< NL Zosterophyllum Penh. (of the classis Zosterophyllopsida sensu Kenrick & Crane) < Gk. zōstēr ζωστήρ girdle, band + phýllon φύλλον leaf]

zy·go·mor·phic (zī´gō môr´fik) adj. of a flower or corolla, having the parts arranged in bilateral symmetry, but not in radial symmetry; bilateral; irregular. [< Gk. zygosis ζυγόσις a joining + morphē μορφή form + -ikos -ικος relating to] —zy´go·mor´phy, n.