David askedm >There is a botanical word I’m looking for it’s something like gradient, >but I don’t think that’s the word. It is used when referring to a species >with a broad distribution which has one form at one end of its >distribution and a very different form at the other end. The two extreme >forms are sometimes considered separate species. But when the >distribution is continuous and every intermediate form is found and there >is no bar to interbreeding, this special word is used, and the population >is considered a single species with disparate extreme forms This is called a continuum. The same term is used in linguistics to describe a series of dialects of a language, the adjacent ones of which may be mutually intelligible, but the extremes of which may not be. Jane McGary >_______________________________________________ >pbs mailing list >pbs@lists.ibiblio.org >http://www.pacificbulbsociety.org/list.php >http://pacificbulbsociety.org/pbswiki/