Different Genus .. same species?!

How can organisms belong to the same species yet different genuses?


Phaseolus vulgaris (Kidney bean)
Hordeum vulgaris (Barley)

It’s just a naming convention, and not a particularly complicated one.

Think of the Genus as a surname and the Species as a christian name. John Smith and John Brown have the same christian name but they aren’t related and nobody would expect them to be simply because they share a christian name. John Smith and Susan Smith would be expected to be related because they share a surname, and so Phaseolus hepatica and *P. vulgaris *would be expected to be related because hey share a Genus
Species names are frequently recycled amongst genera. Genus names are restricted only to related to organisms.

Vulgaris is latin for common, so the word is just that and appears in any number of diseases too.

I hear this tossed around a lot. Aren’t we all related in the end? What is the standard for relatedness? How close do I have to be to someone to be considered “related”?

You are already close enough.

Close enough to whom?

We’re not related in the end, we’re related in the genes.

(Okay, there are a few people I suspect may be related to my end… Ba da dum…)

I have trouble believing this is a serious question, but of course there are different degrees of relatedness between organisms just as there are between people. The members of a genus might be compared to siblings, the members of the same family to first cousins.

When we say things “aren’t related,” we just mean they are comparatively more distantly related.

everyone. Homo sapiens sapiens.

So it’s an arbitrary standard?

10th cousin … not related.

9th cousin … related.

Like I said, it’s relative and has to be taken in context. It would be better to say, “not closely related,” rather than not related.

Not to whom - to what: in this case, a kidney bean.

There is a huge amount of duplication of species names, all in different genera. The species name is typically applied at the discretion of the naturalist who first describes the newly discovered species. Sometimes he will name it after himself, or to honor a colleague, of simply describing some distinctive characteristic.

Most genera have only a few species, usually less than a dozen or two, and within a genus, all that is needed is to not duplicate the specific name. For example, among a genus of North American woodpeckers, there is Picoides nuttallii (named for the ornithologist Thomas Nuttall, for whom a magpie and a poorwill were also named), Picoides borealis (named for its boreal range) and Picoides tridactylis, for its three toes.

“officinalis” is another very common specific name that’s shared across quite a few genera. It basically means “medicinal”. Althaea officinalis, Calendula officinalis, Stachys officinalis, Magnolia officinalis, Melissa officinalis…even an animal example, the common cuttlefish, Sepia officinalis.

This can cause problems when genera are merged, or if a species is moved to a different genus. If the specific name is duplicated in the new expanded genus, then the name of one of the species must be changed. The species name with priority (the one described first) will retain the original name, while the species that was described later must receive a new name.

“Phaseolus” is the name of a genus, but “vulgaris” is not the name of a species. “Phaseolus vulgaris” is the name of a species. “Hordeum vulgaris” is the name of a different species. The two species don’t have the same name; they only have a portion of their name in common.