I recently read an exchange on another garden forum where several people were complaining about botanists tinkering with the names of plants like Philodendron micans, Philodendron scandens Philodendron miduhoi, Philodendron oxycardium, Philodendron acrocardium and others. The truth is they have "tinkered" with nothing. They are simply following hundreds of years of established botanical science. And this did not begin a few years ago! It started almost 180 years ago! The correct species name for all these plants is Philodendron hederaceum. It has been that way since at least 1899 but the knowledge these other names are not valid has been around longer than that! The reason is known as variation. Now, I can hear you saying these plants don't even look alike. And on that you would be right. This species along with many aroid species do not always appear the same. How is that possible? It is quite simple. Within aroids, and Philodendron hederaceum is an aroid species, variation is common, Think of it like human faces. You know many people but those people don't all look alike. They all have different body sizes, different shoe sizes, different color hair, different tones of skin, and often very distinctive facial features which we normally just accept as human or racial differences. And that is the same concept as in the world of plants! Dr. Thomas B. Croat Ph.D., P.A. Schulze Curator of Botany of the Missouri Botanical Garden in St. Louis, MO. once explained in person that if you were to make collections of this species throughout its natural range, which includes the Caribbean, southern Mexico, all of Central America and all of tropical South America you would find countless slight variations. But all those hundreds, possibly thousands of variations have never been granted their own exclusive name. Only a select few which to a botanist somehow appeared distinct were granted such a scientific designation. And most of those were granted incorrectly in the 1800's. But the names that have stuck are well entrenched in the minds of plant collectors. As Dr. Croat explained, "It is simply the nature of evolution." Within the rules of botany it is well established that the very first name ever granted to a species correct to genus becomes the basionym and all attempts to rename that plant simply become synonyms of the basionym once those errors are discovered. As a result, all the commonly used names known by collectors are now simply synonyms of the base species and are no longer valid within science. They are still sometimes used, but are no longer the prime species' name. It is plant collectors that wish to continue to use outdated names because we feel we must put a name on any leaf that looks slightly different! But to a scientist they are all one single species. Despite the theory that botanists have recently begun to "tinker" with names this has been going on for well over 100 years. Botanist Heinrich Wilhelm Schott (1794 to 1865) however understood the problem. He had already transferred Arum hederaceum (the first name given the species) to the genus Philodendron in 1829 because he realized that plant was not an Arum but a Philodendron. In 1856 Schott also placed Philodendron hederaceum into synonymy under his newly described Philodendron jacquinii. However, he included P. hederaceum in his grex Macrobelium while placing other synonyms of P. hederaceum within grex Solenosterigma. The names transferred along with the first were P. scandens, P. oxycardium, P. micans and others. In 1899 botanist Gustav Heinrich Adolf Engler (1844 to 1930) treated the species we now accept as Philodendron hederaceum as four distinct species which included Philodendron scandens, P. oxycardium, P. micans and a name no longer used. Despite the confusion, botanist Julian Alfred Steyermark (1909 to 1988) in 1958 correctly dealt with the taxonomy of P. hederaceum citing P. scandens, P. oxycardium and P. miduhoi as synonyms. But then in 1963 botanist George Bunting attempted again to grant a new name that is now clearly understood to simply be Philodendron hederaceum, Other noted botanists have written opinions all along the way about the variation within this species. So the problem of incorrect multiple names for a single species has long been understood and attempts were made to correct the problem many years ago. Still, even in our modern era it is confusing, even to the occasional trained botanist. But collectors just don't always like to accept botanical science. Despite beliefs posted on the internet that botanists are perpetually toying with names and are "constantly changing" those names. The scientific fact is they are simply following the rules of botany. No one has changed anything! These scientists are simply following those rules as defined for centuries by botanical science. Here's another way to consider it. We know there are many races within our human species but only a single species which is Homo sapiens. With most, the only major difference is skin color or some facial feature such as slanted eyes. But which race is the "basionym" or base species? Oh would that get complicated and offensive if someone were to claim the Negroid race, or the Anglo race, or the Asian race was the base species and all others needed a new name which science would immediately declare as a "synonym". No one with morals is even going to touch that argument! As a result we are happy to just divide our species into races. But we all also understand that none of those races have any major scientific difference when a doctor is called in to operate. Virtually any well trained physician knows all the body parts of any race! So, when a botanist determines there is no scientific difference in Philodendron oxycardium, Philodendron scandens, Philodendron miduhoi and Philodendron hederaceum we are left only to go back to the first name correct to genus ever assigned and that name is Philodendron hederaceum. It doesn't work well for plant collectors but it works fine for science. Collectors are the ones that perpetuate the confusion by using multiple names. Botanists did not "change" the name of anything! I've written an article which explains all of this is much more detail if you care to investigate further: http://www.exoticrainforest.com/Philodendron hederaceum pc.html But don't be saying botanists are changing the name of your favorite little plant. It just didn't happen. We are the ones that continue to perpetuate names that are not scientifically valid any longer.