Ecotype can be defined as a physiologically induced variation initiated by long term occupation within a definable ecological community but one that is not genetically distinct from other members of the species that occur in other ecological communities. Such variations may not be significant enough to warrant taxonomic recognition. Among these variations may be the amount of pubescence on the stems, internode spacing, and even the amount of occurrence of stomates. Whatever the variation is it can be related to some significant environmental stress in the habitat.