In article ,
P van Rijckevorsel wrote:

Not to mention that an epithet based on Mr/Dr/Sir/Rev/Whatever Behen should
be "behenii" / "beheniae" (if female) or behenianus/um/a

Okay, I took some Latin in high school in Palaeolithic times, and I
realize that botanical Latin is not quite the same, but can someone
summarize how specific and generic epithets are derived from people's
names?

I think it's the genitive (possessive) case, for specific epithets,
right? But first you have to Latinise the person's name, if it isn't
already, by adding -us to a male name and -a to a female name. So
something named after Anna would be annae, but after Ingrid would be
ingridae, and if it were named after Julius, it would be julii but
after Mr. Smith it would be smithii, because you first Latinise Ingrid
to Ingrida and Smith to Smithus. If it's named after two guys named
Smith, or Mr. and Ms. Smith, it's smithorum, but I don't recall the
feminine genitive declension so dunno what it would be if named after
two women named Smith. Now human beings are generally regarded as
being of only two genders, so you don't have to worry about the neuter
gender in this (ouch) case, but I'm not clear on how you manage
naming something after Mr. Anna or Ms. Julius, or for that matter,
after a man or woman whose name has a Latin neuter ending in the
nominative case, -um.

IIRC, in Latin, possessives take the gender of the owner, not the thing
owned, so when the specific epithet is derived from a person's name, it
doesn't have to agree in gender with the generic name.

Rambling on and continuing to display my ignorance, generic names are
nominative case, I think, but I'm not clear on how personal names are
Latinised in this context, except there seem to be a lot of -ia and
-iana suffixes.

One last bit of possibly incorrect knowledge, when the specific epithet
derives from a place name, the place name is Latinised by adding -ense
for a feminine(?) generic name, or -ensis for a masculine or neuter(?)
generic name. Well, sometimes - I've seen e.g. peruana and I think
peruviana too.

Then there's the problem of Latinising Greek. What I want to know is
if the genus Iris is in the Iridaceae, and I want to name a new plant
after Iris who frequently posts on the newgroup, is the specific
epithet irisae or iridae? So there. (Don't worry, Iris, it'll never
happen, at least from me.)