I think I know why Lobelia S.B. is called Lobelia

[shadowfax]

I think Tom Shippey convincingly formulates the theory that Sackville Baggins is a wordplay on cul-de-sac and his general disapproval of using French words to describe things for which there are decent Engish words. Of course cul-de-sac is not even proper French but an anglicised usage of French to appear eduacted or intellectual.

Bag End is thus a literal English translation of cul de sac (bottom of a bag). Ville (before it came to mean town) came from possibly celtic origins denoting a settlement and thus could also loosely mean the same as end does in English place names. Thus sackville is bag end and the name Sackville Baggins is thus a meaningless repetition of the same thing.

Baggins is of course also another wordplay, as Bilbo (or so Gandalf claims) is a burglar (actually a misinterpretation of the term burgher, for a bourgeouis citizen) and a burglar is obviously somebody who steals, or "bags" things. Of couzrse he did end up bagging both the Ring and the arkenstone, and as such proved a good "bagger".

Colloquially, at least to an Oxford don in Tolkien's day, a baggins was also a light meal. And Bilbo was certainly one who liked to tuck into his meals.

Of course Hobb Lane also comes into it. Tolkien obviosuly didn't mind combining several jokes and references into one.