I love this category. On the more 'hypothetical' side that I've always really loved Ciruela and Almendra . A few others I like that I can think of offhand, including fruits and vegetables...
Traditional:
AngélicaAmaranto
Artemisa
Verónica
Hypothetical:
Azafrán
Castaña
Castaño
Manzana
Berenjena
Higuera
Cedro
Ciprés
Piñón
Galanto
Álamo
Avellano
Alhelí
Roble
Pensamiento
Palmera
Palmito
Fresa - the phrase "niña fresa" probably makes this one a nonstarter, though
Cereza
Peonía
Avena
Trigo
Sandía
MoraLupino
From your list, my favorites are:
MargaritaRosaIrisAmapola
JazmínBegonia
Miosotis - love this word and pronunciation, but prefer the French spelling Myosotis
LilaLaurel - love the Spanish pronunciation
FlorPasionaria
Adelfa
JacintoLirio - even though the noun is masculine, I've always thought this could work for a girl
Romero
Tulipán
Girasol
Loto