I don't know if all these are actually used, but I think they are all OK to use - I mean, it's not like naming someone "Mugwort" or "Toadstool".
Can you come up with more?
(And yes, I DO know that mushrooms are not really plants, but who cares?)
AcaciaAmaryllisAmbrosiaAnemoneApple
AshAspenAster
AzaleaBluebell
Camomile
Carnation
Chanterelle
Chrysanthemum
Cinnamon
ClematisCloverColumbineCorianderDaffodilDahliaDaisyEglantineElm
FernFleur-de-lis
HazelHollyHyacinthIrisIvyJacaranda
JasmineLaurelLavenderLilacLilyLindenLotusMagnoliaMaple
MarigoldMimosa
MyrtleOleander
OlivePansyPeonyPetuniaPoppyPrimroseRoseRowanSaffronSageTansyTulip
VioletWillowZinnia
Does the sea exist
Because of our longing?
My PNL
http://www.behindthename.com/pnl/3258/61573