monomorphic

adjective

1. Biology. having only one form.
2. of the same or of an essentially similar type of structure.

adjective

1. (of an individual organism) showing little or no change in structure during the entire life history
2. (of a species) existing or having parts that exist in only one form
3. (of a chemical compound) having only one crystalline form

adj.

1. Having only one form, as one crystal form.
2. Having one or the same genotype, form, or structure through a series of developmental changes.