There's a discussion going on over at Wikipedia regarding the naming convention for articles about plants.  In general, article titles are supposed to be the "most common" name for the thing in English.  But when you're trying to compile "the sum total of human knowledge", that simple rule can be problematic.  Do you really want to use "the most common" name, or do you want to use the most accurate name?  After all, Wikipedia seeks to be an encyclopaedia.

Things get far worse when you try to write articles about plant species.  There are about a quarter million species of flowering plants.  Most of them lack common names in English.  But where they exist, common names vary from place to place.  To make matters worse, a single common name will often refer to more than one species of plant.  Over the course of the discussion, Curtis Clark wrote:

I wonder if we don't read too much into the use of common names by assuming they refer to species.--Curtis Clark (talk) 16:23, 29 December 2008 (UTC)

Every now and then you come across that statement that bridges a set of disparate ideas.  I remember the first time I was told that no, you can't simply translate a common name into the equivalent scientific name - you need a specimen.  That seemed awfully pedantic.  But gradually I came to understand that often a common name wasn't nearly precise enough to identify a plant for sure.  Most people don't pay attention to plants in the same way that they pay attention to animals.

Most people suffer from plant blindness.  The term was coined in 1999 by James Wandersee and Elizabeth Schlusser in an article in The American Biology Teacher (JSTOR subscription required).  In it, they defined plant blindness as

• the inability to see or notice plants in one's environment
• the inability to recognise the importance of plants in the biosphere and in human affairs
• the inability to appreciate teh aesthetic and unique biological features of the life forms that belong to the Plant Kingdom
• the misguided anthropocentric ranking of plants as inferior to animals, and thus as unworthy of consideration.

They developed the idea further in an article in the Plant Science Bulletin in 2001. Last year in the New York Times Natalie Angier wrote:

According to Peter H. Raven, director of the Missouri Botanical Garden,many of us suffer from an insidious condition called “plant blindness.” We barely notice plants, can rarely identify them and find them incomparably inert. Do you think that you will ever see a coma as vegetative as a tree? “Animals are much more vivid to the average person than plants are,” Dr. Raven said, “and some people aren’t even sure that plants are alive.”

If most people are plant blind, how much can we expect them to notice the subtle features that distinguish one species from its close relatives?