Anytime there's one or more varieties, and a plant is labelled just Epidendrum magnoliae, there can be some doubt as to which variety it is. Repeating the species name is just a way of emphasizing that this the same as the species type and not some other variety.

I think someone just invented Den. tetragonum var. tetragonum. It is just listed as Den. tetragonum in the book Native Orchids of Australia and i have never seen an orchid labeled Den. tetragonum var tetragonum in many many years of orchid growing.
I am certainly not going to change the tag on my plant.

Zach - OK, but there doesn't seem to be consistency in the orchid world. For instance, is Catt bicolor also know as Catt bicolor var. bicolor to distinguish it from Catt. bicolor var. caerulea or var. lewisii or var. mearuresiana or var. olocheilos? The same goes with Calypso bulbosa. Is that one also referred to as Calypso bulbosa var. bulbosa to distinguish it from the other varieties? I'm asking because I really don't know. Maybe they are.

Arthur - Found this:

Here the author says Den tetragonum var. tetragonum is now known simply as Den. tetragonum.

http://www.anos.org.au/information/articles/species/dendrobium.htm#Dendrobium%20tetragonum

Here it's still listed as Dend tetragonum var. tetragonum

http://www.oscov.asn.au/articles/tetrainfl.htm

K

Kevin, if i remember i'll ask the native orchid guru at the orchid society meeting tonight if he has ever seen it labelled as D. tetragonum var. tetragonum.
There are numerous varieties of Cattleya intermedia. Hopefully there are none called "intermedia var.intermedia"

Kevin
is that the same as"_______________ x Itself"? I always wondered about that
Clara

Spoke to the Australian Native guru and he says that Den. tetragonum var. tetragonum is an acceptable version of the name.

Speculation, but it seems to me that the nomenclature is a back-construction done for clarity after multiple varieties have been described. I.e., Originally called D. tetragonum, but after D. tetragonum var. album (or whatever) is described, D. tetragonum var. tetragonum is introduced to fully describe the original plant type. I'm agreeing with Zach, with the addition I would expect many people to drop the var. tetragonum part because it appears redundant.

Other example I can think of is Cypripedium parviflorum, which is called parviflorum var. parviflorum if you believe that Cypripedium pubescens is more properly parviflorum var. pubescens, and just C. parviflorum if you don't!

Clara - Nope.

tee - Thank you. Redundant was the word I was looking for.

OK, I'm getting the impression this is something that is not commonly or consistently done by taxonomists. In the case of Epi magnoliae there may have been a specific reason to do it, but I haven't been able to find it. Maybe if I were to read through some of the orchid literature of the day, it would explain why. Same goes for Dend tetragonum.

It still seems odd that someone would feel the need to add var. magnoliae to Epi magnoliae since there is only one other variety - a larger growing plant called Epi. magnoliae var. mexicanum.

It still makes me wonder why it was done for some plants and not others. Guess I'll never know for sure.

K

It it follows the laws of scientific nomenclature based upon the latest edition of International codes of zoological or botanical nomenclature.

If there is more than one variety the variety of the type specimen carries the repetetive nomen, and others are given their own distinctive varietal name. It's the same with subspecies. If there is only one form then it is not given a varietal name.

If the variety is not listed for a species with more than one variety there is no way to know which is being discussed...It DOES NOT mean that the typical variety is being discussed. The species name "Epi magnoliae" encompases both forms. Epi. magnoliae magnolia (if subspecies) or Epi magnolia var. magnoliae (if varieties) indicates which of the varieties.

Whatever the yahoo owning the nursery puts on his tags is up to him. He may not know what variety he has, or is ignorant that there are more than one variety.

Did you copy that from some place? English please. I have no idea what all that means.

K

Basically, the redundant name indicates "the normal one", which is what most people would refer to it as instead of the nomenclaturally proper method, the dominant coloration/form. var magnolia helps to distinguish what you normally think of as magnolia from var album or var coerulea and any other variety.

Kevin, just to clarify, the varieties of Dendrobium tetragonum have been split into different species. The first article you cited discusses tetragonums in the context of the varieties being raised to species level, therefore D.tetragonum is acceptable. The second article uses the older nomenclature, therefore, tetragonum var tetragonum is correct. (I'm not touching Tetrabaculum with a forty foot pole on a web forum).

Using repetitive variety names is not uncommon. Actually it's the norm where varieties are described within species. It's probably not common to see such nomenclature amongst cultivated orchids as there is, for various reasons, intense interest in raising orchid varieties to species level, varieties are often line bred and you are often lucky to get species labelled correctly let alone varieties.

Where a species consists of two varieties, the variety described as the 'type species' is normally given the repetitive name. Why? Probably a cross between 'the way it's done' and ease of tracking and using nomenclature- ie you don't need wade through an index of names to read historical records and when varieties are elevated to species level, it's a no brainer to see which variety should be returned to the original species name. Taxonomy is filled with instances of mistakes so why add to the problem. Moreso the problem is that if we don't record the varietal name of the 'type', when you get hold of a plant labelled 'Dendrobium tetragunum', how do you know if it's the type species or a result of line breeding varieties.
Andrew