Great mullein 
Greater Yellow-Rattle 
Greek Sage 
Green chireta 
Green Figwort 
Green Olive Tree 
Green Rosemary 
Grey Field-speedwell 
Grey Mangrove 
Gymnostachyum febrifugum 
Haberlea 
Hairy Broomrape 
Hairy eyebright 
Hairy Indian paintbrush 
Hairy Skullcap 
Halleria ligustrifolia 
Harlequin fuchsia bush 
Harlequin Glorybower 
Harsh Paintbrush 
Hartweg's Beardtongue 
Harveya alectroides 
Heart-leaf Velvet Bur 
Heath Speedwell 
Hebe epacridea