nomenclature question

[pitik101]

this would most likely fall into kmarch's realm

I've been getting deeper into species category and have lately paying much attention to articles, literatures, books thats is related to orchids. Couple of words in the naming system confuses me right now

When and where does "var" and "fma" be used? Where do we draw the line between "form" and "variety"? and what is the reason why both of them may appear on the species name..for example "Dendrobium sanderae var major fma album"..why cant it be called "Dendrobium sanderae var major var album"

When and where does "alba" and "album" be used? Since both are the same (right? ) can they be used interchangeably?

[kmarch]

Originally Posted by pitik101

Couple of words in the naming system confuses me right now.....When and where does "var" and "fma" be used? Where do we draw the line between "form" and "variety"?

If you haven't yet, give my forum article on orchid nomenclature a read. It touches upon "var" and "fma" but I'll expand upon them here.

Varieties and forma are what we call infraspecific epithets, literaly names within a species. There are 5 ranks of infraspecific ephitets. In descending order they are:
subspecies (subsp.),
variety (var.),
subvariety (subvar.),
forma (f.), and
subforma (subf.).

In the same way that orchids are divided and organized into smaller and smaller groups according to their common characteristics using genus, subgenus, and species ranking, these groupings continue beyond the species level using the infraspecific names listed above. Taxonomists assign an infraspecific epithet to a species when significant differences exist within a species.

(The botanists on the forum may feel free to correct or clarify my statements if necessary) Subspecies, variety, and subvariety (though this last one is rarely used in orchids) are often used when there are genetically stable, naturally occuring, structural variations within a species. For example, Paph philippinense var robelenii has longer, darker and more tightly twisted petals than the regular philipinense yet both are clearly philippinense in other respects.

The use of the rank of forma is usually used to describe different, genetically stable, naturally occuring, colour forms that are found within a species. Orchids that come in white versions (alba, album) or yellow (flava, flavum) are usually forma (commonly refered to as forms). And example of this would be the yellow Phrag besseae f.flavum. The rank of subforma is also rare and I've never seen it used on an orchid.

Now you've probably noticed I have repeatedly used the qualifiers "genetically stable" and "naturally occuring." This is because this scientific naming system is used exclusively for naturally occuring plants which reproduce themselves without the intervention of humans. Line bred species, mutations, and other forms of species which are not found in nature and which do not reproduce themselves in nature are not to have infraspecific ephitets. None of these ranks (var., forma, etc., etc.) would be used with a hybrid of any kind. If oyu see a hybrid with a "var." or a "forma" or "form" you'll know right away that something's amiss.

Originally Posted by pitik101

and what is the reason why both of them may appear on the species name..for example "Dendrobium sanderae var major fma album"..why cant it be called "Dendrobium sanderae var major var album"

It can't be called Den sanderae var. major var. album because one species can't be two different varieties at the same time. Varieties within a species represent naturally occuring, genetically stable differences found within that species. Den. sanderae var major has bigger flowers and flowers at a different time of the year form other varieties of sanderae. Within the group of orchids identified as Den sanderae var major, some are aparently all white and so are distinguished with the rank of forma album (f. album or fma. album).

As an aside, I'm suspicious of this particular name especially since Den sanderae flowers are white to begin with with very little colouration. I've never seen described a fma. album and would be suprised if it occured naturally.

Originally Posted by pitik101

When and where does "alba" and "album" be used? Since both are the same (right? ) can they be used interchangeably?

"Alba" and "album" mean the same thing (white form) but may not be used interchangeably. We are now leaving the world of orchid nomenclature and entering the world of Latin grammar. Latin is a gendered language. Nouns have a gender and the form of the adjectives describing those nouns have to match the gender of the noun. If the name of the genus is feminine, "alba" is used. If the name is gender neutral, "album" is used. If the genus ends in "um" like Oncidium, Dendrobium, or Paphiopedilum, the gender is neutral and "album" is used (note album ends in "um"). If the genus ends in "a", "is", "es", "e", "ix", or "ys" it is feminine, and "alba" is used. Rarely one might encounter a white form of a flower whos genus ends in "us" which is a masculine ending and which would use "albus". The ending "as" can be either masculine or feminine and you have to look at the species name to determine the gender. (Fun eh!?!?!?!?!)

Hopefully this answers more questions than it raises.

[pitik101]

thanks for that wonderful...information loaded reply. I've got enlightened with a lot of things im concerned.

now got to remember that alba ang album are a mr and ms thing ...

Yes this is fun...some curve balls along the ways are always fun in the realm of learning.

Thank you!