Mr Smith and his rhododendron indicum

Nurseries started cultivating the original wild material as early as 1850.
They started selling plants with name-tags; names that were valid at that time.

So Mr. Smith, an enthusiastic 19th century gardener, is interesting in these 'new plants' called rhododendron. He buys himself (in 1862) a fine shrub with name-tag: indicum.

Rh. indicum does fine and gives nice flowers during spring. Mr. Smith is proud and shows his garden to all his neighbours.

Then disaster (=scientific discovery) strikes: someone found a variation of Rh. indicum. Everyone agrees on the fact that this must be a variation or even a sub-species.
The new species gets the name of his discoverer: Rh. indicum var smithii (coincidence exists)
As a logical consequence the old name "indicum" is no longer good: the old "indicum" will from now on be called indicum var indicum.
The nurseries start changing name-tags and Mr. Smith's rhodo does not longer exist: he has to figure out himself whether he has variety 'indicum' or variety 'smithii'
(naturally he hopes for smithii).

indicum var indicum or smithii?
Mr. Smith studies all known literature and concludes: I have a rhododendron indicum var smithii
He rapidly changes the name-tag. But then.. 3 years later...disaster (= scientific discovery): someone finds out that variety smithii does not belong to species indicum!
In fact it is a new subgenus and indicum var smithii is from now on called Rh. pulchrum. (and Rh. indicum var indicum becomes plain 'Rh. indicum' again)

Mr. Smith is very disappointed hearing this news and decides not to change the name-tag for a couple of months.
(By the way, he has been to the Botanical Gardens of Kent and there they still have the name-tag indicum var smithii on their there is still hope.)

pulchrum or indicum?
Then disaster (=scientific discovery) again: someone with a microscope has done a discovery: Rh. pulchrum is in fact a 'natural hybrid' (so it is Rh. x pulchrum) between Rh. ledifolium x Rh. indicum.
So... Mr. Smith might own an indicum (possible), not an indicum smithii (no longer existing) or perhaps a pulchrum but that is 'just' a hybrid.
He stops gardening and takes up golfing.

Now this story is made up. The time-frame is made up. But the names of the rhododendrons mentioned (and the name-changes) are NOT.
(there actually once was an indicum var smithii, and there is a pulchrum)

x pulchrum
In fact there have been as many as 18 varieties of indicum (all listed on this website). At the moment there is only 1 (Rh. indicum) left. The rest turned out to be simsii, kiusianum, obtusum and so on.

So when you take pictures of rhododendrons (in a botanical garden f.i.) you might see name-tags as: Rh. indicum var japonicum, or Rh. indicum var sinensis.
All these names are outdated. But a lot of literature still mentions these plants (books have not been reprinted), a lot of name-tags in gardens have not been changed.
(and websites often are not updated!)