Okay, it looks like you're right - there is a rose named Perdita!
I've just found it, here:
http://www.treloar-roses.com.au/files/perdita.htm
The page says that it was bred in 1983, and won a couple of awards in 1984. Since this was before Perdita Weeks was born, it is indeed theoretically possible that she was named after the rose
However, it seems rather unlikely to me. "Perdita" was already in use as a girls' name long before that particular variety of rose came into existence. There's a page about other uses of the name, here:
http://homepages.inf.ed.ac.uk/perdita/perdita.html
The name is Latin for "lost", and was used - originally, as far as I can tell - by William Shakespeare for a character in his play
The Winter's Tale
. In the play, the King and Queen of Sicilia - Leontes and Hermione - have a baby daughter. But Leontes thinks that his wife has been having an affair, and doesn't believe the baby is his. So the baby is taken away into exile, and, basically,
lost
. Hence the name. Clever, isn't it?
My guess is that Perdita Weeks's name comes either directly or indirectly from the Shakespeare character. I can't think why her parents would give her that name, thought. Calling a baby "lost" doesn't seem all that nice to me. What are they trying to say, exactly?
Anyway, time to end this message. My advice to you now is to leave the computer, go and have a walk in the park, and admire all the pretty flowers

i'm sure perdita was the name of a blossom or something.well i'm from london the only time i ever see flowers in is a shop of the parksad really
Thunderbirds Aren't Slow

I didn't say that Perdita wasn't in it. Read my message again! I did hint that I wasn't
sure
she was, though. The mere fact that the IMDb says she was doesn't mean that it's true. I've seen quite a few credits on other pages that have been totally made up. So you can never be 100% sure from just the IMDb alone; you have to check with other sources.
Anyway, if you read the credits on the IMDb page, you'll see that Honeysuckle Weeks is listed somewhere near the top (should be
the
top, really), and that Perdita Weeks is listed rather lower down, and without even a character name. (I'm fairly sure that Rollo wasn't given a character name to start with, either, but he seems to have been given one now.) Although it isn't always the case that major characters are credited higher up than minor ones, it's still strong evidence that Honeysuckle played a more prominent role in the series than Perdita, don't you think?
I didn't watch
The Queen's Nose
in its early days, but I know that it used to star Victoria Shalet as Harmony Parker. Incidentally, I'm actually getting some episodes of the first series on video soon, so I can cat2000ch up a bit. Anyway, according to the IMDb, Victoria Shalet played Jude in
Goggle Eyes
. I hope that helps make things a bit clearer
I don't know what you mean about all the girls being named after flowers, though. I know that honeysuckle is a plant, but there isn't a plant called a "perdita", is there?

then why the hell is she listws in credits if she wasn;t in it. i thought her sister was in the queens nose, a tv show from when i was a kidi don't know all the girls are named after flowers, it is all so confusing
Thunderbirds Aren't Slow

It was Honeysuckle Weeks (now best known as Sam Stewart in
Foyle's War
) who starred in
Goggle Eyes
, not her younger sister Perdita.
I didn't watch the programme when it was on, although I did see random snatches of it, as other people in the house were watching it. All I can remember is how pretty Ms. Weeks was.
I wish they'd show it again, or release it on DVD or something, so that I could watch it properly.
According to the IMDb, both of Honeysuckle Weeks's younger siblings - Perdita and Rollo - appeared in the programme, but it doesn't name their characters, so I expect they only played minor parts in it, if any.
I've only seen Perdita in
Midsomer Murders
(a
horrible
episode!), the Sherlock Holmes thing, and maybe briefly in
Stig of the Dump
, although I didn't watch that properly, and didn't realise that she was in it at the time. She is a good actress, though. They're a remarkably talented family as a whole.