Why is the Rhamnaceae only divided into tribes?

I’m aware that families, subfamilies and tribes are meaningless ranks made up entirely by humans, but most families that are big enough are divided into subfamilies. If those subfamilies are big enough, they are divided into tribes. But the Rhamnaceae totally skips the subfamilies and is divided directly into tribes for no apparent reason. Anyone know if there is an interesting story behind this?

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I’d suggest documenting stories like this in a collective blog. Then, revisit the data along with how the data is stored. Could Rhamnaceae be stored in a different structure that is more consistent with the rest of taxonomy while preserving the story in the blog?

The reason this might be so important is that more consistent nodes might further support bundling of nodes which might be useful when applying the science.

Well, if among many genuses (:o) some are more closely related, why not group those genera in a tribe? And if among many tribes, it is shown one day that some are more closely related, why not group those tribes in a subfamily?

Would it be correct to say that it’s a secondary grouping somewhat independent of the main grouping? … “some are more closely related” ~ does “some” refer to genera :o) or species

oh… nevermind lol “why not group those genera”… you’re referring to genera but you used both words. brain sleepy

If they are further instances of nested groupings, might they one day further support applied science?

Role based bundling of hierarchical nodes…

A restorationist working on a woodlot in the midwest is focused on a specimen in the Euonymus genus. The iNat glasses, having been set to “newb” and aware of location, have identified the plant as “Euonymus” but have not issued a prompt of “encourage” or “discourage”. Upon the blinking of the right eye, the glasses adjust to “Euonymus alatus - Burning Bush”, and the prompting is revealed as “discourage”.

In the other example the bundling was done at the species level, in this example it’s at genus. Increasingly complex data is revealed upon request. Without request the identification of leaves fluttering in the breeze is more fixed at a higher level.

In this example the nodes in the hierarchy would store a list of roles for which each node would appear as bundled. There would need to be a way to set the role on the viewing device (glasses). It assumes the names shown in the viewing device are received as an object containing more than just latin/common names.

Some example roles…
newb - bundle at a level understandable to a teenager (or stranger from a different vertical)
botanist - ignore everything but plants
birder - ignore everything but birds
restorationist - bundle based on location / introduced

Well, I do not believe there is any standardization for what a subfamily or a tribe is. So if you notice the genera in the family clump into groups, why not call those groups subfamilies?

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or why not cautiously start small with e.g. ‘subtribe’ ? (the goal being to lump closely-related genera together, rather than splitting broadly-encompassing units)

If the taxonomy is based on cladistics it would preumably be because the group of tribes constitute a clade that clusters with other clades that are families, not subfamilies.

I think subfamily is supposed to be used mainly when there are an unwieldy amount of tribes and/or there are useful natural groupings between tribe and family:

So, Rhamnaceae isn’t skipping subfamilies, it just isn’t adding them.

Your mileage may vary with respect to whether this is consistent with how it is done on the site or in practice. We’re theoretically only supposed to add these extra ranks if they are useful or included in the taxonomic framework we reference. We arguably may add them more than is actually useful in many cases. The extra ranks add more database complexity and are more work to maintain if they change.

The source for the tribes is “A Revision of the Tribal Classification of Rhamnaceae” which I think you can read for free at the link without a login. They actually do name several ‘informal infra-familial groups’ above tribe and below family, but didn’t call them ‘subfamilies’ so we wouldn’t have them on inat.