Quote[/b] (BobZ @ July 13 2004,6:03)]I beg to differ.
The ICPS database lists
H. tatei {Gleason}
H. tatei {Gleason} f.macdonaldae {(Gleason) Steyerm.}
H. tatei {Gleason} var.neblinae {(Maguire) Steyerm.}
H. tatei {Gleason} var.neblinae {(Maguire) Steyerm.} f.parva {(Maguire) Steyerm.}
Sloppy use of the name H. tatei without any qualifier could leave in question the exact form or variety of the plant. By specifying H. tatei var. tatei, even though that is not a "recognized" variety, it clearly identifies the plant as not being one of the other forms or varieties.
Similarly, with S. purpurea, there is no "recognized" S. purpurea var. purpurea. S. purpurea is the name given to the plant that grows in the northeastern U.S and Canada. S. purpurea var. venosa is the southern variety. However, sloppy use of the name S. purpurea can lead to confusion whether the plant is the northern or southern form. Consequently, to save confusion, the northern form is sometimes referred to as S. purpurea purpurea.