monocotyledones

from The Century Dictionary.

• noun A natural class of flowering plants, having a single seed-leaf or cotyledon in the embryo.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun comprising seed plants that produce an embryo with a single cotyledon and parallel-veined leaves: includes grasses and lilies and palms and orchids; divided into four subclasses or superorders: Alismatidae; Arecidae; Commelinidae; and Liliidae