anisomerous

from The Century Dictionary.

• In botany, unsymmetrical: applied to flowers which have not the same number of parts in each circle.
• In odontography, having the transverse ridges of successive molar teeth increasing in number by more than one, as in the mastodons.

from the GNU version of the Collaborative International Dictionary of English.

• adjective (Bot.) Having the number of floral organs unequal, as four petals and six stamens.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• adjective botany Having the number of floral organs unequal.