I think it's always "Rhodies" in the blue collar vernacular. Kinda simplifies things. ;Â)

Language and usage are always interesting though so I hope someone else might have some (more useful) insight.

Here are some replies I got off line:

Susan wrote:
'rhododendron' is a second declension neuter noun in ancient Greek. It's correct plural is 'rhododendra'. But as with so many things, very few people use the correct form unless they are rather pedantic classicists. I mean, how many people use the word 'agendum' as a singular and 'agenda' strictly as a plural? And that's only Latin!

John wrote:
Question: Greek or otherwise how can you hybridize with a neuter noun? Maybe this is the reason so few of our crosses take.

Lyn wrote:
As far as the plural of Rhododendron goes, one needs to rember that although the International Code of Botanical Nomenclature considers this Greek-derived word to be "Latin", we do not have to. My preferred English plural for the common name is Rhododendrons (or rhododendrons, allowing for preferences as to font). I have no plural for the taxon name "Rhododendron" because, by definition, there can only be one of them.

Smart folks! Thanks for sharing their knowledge.

lol, I like John's comment best! I honestly hadn't even considered the etymology before, "rose-tree", much less the plural form(s). I guess that exposes me as being someone fairly new to rhododendra ;Â)

As far as the proper plural form goes I think I'll just play it safe by keeping my primary interest deciduous azaleas.

Cool topic.

Well, I'll be keeping up with this issue....I won't be able to sleep until this is resolved!!!

Hmm...language "correctness" is usually set by common usage. So I did some hunting so see what is most common.

A quick Google search resulted in ~987,000 hits for rhododendrons but only 477 for rhododendra. That's a pretty solid tip o' the scales toward rhododendrons.

I also checked the American Heritage Dictionary, the Random House Unabridged Dictionary, AND the Merriam-Webster Dictionary (all in searchable electronic format--gotta love libraries). None had entries for rhododendra, but all returned results for rhododenrons.

Finally, the American Rhododendron Society uses rhododendrons. (See http://www.rhododendron.org/)

I got an authoritative answer from Ken Cox who is a rhododendron explorer and prolific author of Rhododendron texts. Here is what he said:

"You say 3 species of Rhododendron with a capital letter and italics, to show that this is a genus in Latin."

"However the same word can also be used to refer to the individual plant(s) too in this case, as this is really an 'English' word now, as far as I am concerned, is should be '3 rhododendrons'. I don't care for the Greek rhododendra much. All English words are derived from other languages: French, German, Latin, Greek, but we have decided to apply a universal rule that plural words are made by adding an 's'. The BBC worries about this issue greatly, as there comes a point when a word like 'stadium' which is Latin, with a plural 'stadia' becomes an English word and then the plural is 'stadiums'. They feel the need to issue guidelines on such words."

Examples of usage of the genus name are:

"Members of [italic: Rhododendron] are Ericaceous and include azaleas."

"[italic: R. occidentale] and [italic: R. viscosum] are native
American [italic: Rhododendron] species and are deciduous azaleas."