Lilies have flower parts in multiples of three and vascular bundles scattered throughout their stems. corn plants have fibrous roots and leaves with parallel veins. roses have tap roots and two cotyledons. would you categorize lilies with corn plants or roses

Since lilies have features similar to corn then they are set to be in the same categories. Since both are monocots unlike roses who are dicots. Monocots or monocotyledons have seeds that usually contain only one embryonic leaf. In the other hand, dicotyledon have embryos with two cotyledons.