There is a world of confusion in the scientific names of plants, and even more in the common names.

Taxonomists are forever changing plant scientific names, most often by deciding they should be classed in a different genus or species than they currently are.

Botanical naming becomes even more confused because of incorrect Latin spelling. An example is the epithet you call 'Argenicostriatus.' The correct spelling is 'argenteostriatus.' It's an epithet applied to a bamboo, Pleioblastus 'argenteostriatus' and to Acorus calamus 'argenteostriatus.' It was invented by a botanist named Eduard August von Regel. When you see a botanical name with (Regel) following it, you know the plant was named by this fellow.

Another example is what you call Acorus gramincus 'Variegatus.' The correct spelling is Acorus gramineus 'Variegatus.' It happens all the time, and can be found in books, on plant labels and everywhere else the names are cited.

Plants are also frequently mis-labeled. Imagine a grower, receiving a delivery of thousands of starts for hundreds of different varieties of ornamental grasses. The starts (liners) are tiny, and can frequently look very much like one another. It isn't hard to see how they could inadvertently place the wrong label in a pot or two.

"what kind of terminology is "Bandera dulce multicolor""

Simple. Bandera dulce is Spanish for Sweet Flag, so you have an example of a common name in another language.

'Argenteostriatus' is synonymous with 'Variegatus' and is actually the preferred/accepted name as it was assigned first. One encounters variegatus more often as it is far easier to say and to understand and has become pretty widely accepted although not entirely correct :-) Synonymous cultivar names are not all that uncommon although there is only one that is currently recognized by taxonomic authorities. And you've already figured out common names are a confusing, often regional mish-mash and really have no validity other than being a popular nickname. Translated into botanical Latin, 'argenteostriatus' means "gold striped" and refers to the creamy yellow-white striping on the plant. The intensity of the coloring is variable, depending on the source of the stock and where/how it was grown.

FWIW, Acorus is not an ornamental grass at all but a flowering perennial in the aroid family, Araceae. The specific epithet 'gramineus' refers to the old family name for ornamental grasses, Graminaceae (now Poaceae) and means "grass-like". You will often encounter descriptors like that with species names and sometimes as well with older cultivar names (like the argenteostriatus/variegatus thing). However, current taxonomic requirements prohibits Latinized cultivar names from being used any longer with new cultivars.

Thank you donn and gg, your posts were most enlightening and would be most happy to discuss nearly anything, being dalehileman@me.com