Interesting ! .... but I can only discuss, not give an easy answer.
From your pre-digital experience you know the variety of ways (all of them labour intensive........Your only advantage now is that you can cataogue much faster with a keyboard than a pen.
I suggest start with a database like Access, (there is a handful to begin with). But if you are familiar with Access you can set up your database to suit your wild flower collection only.
Then accept that each catalogued photo has a unique file number starting with 1 .... and let other "fields" be identified by text characters.
You will have to print out a key letter for each field to have in front of you so that when you are renaming your digital photos for the archive you can use the file number, followed by the letter entries which best describe each pic.
Probably all nonsense, and someone may come up with ideal software, though I doubt it!
No harm in airing one tedious way to do it?