Ghost-Men 
Glossonema boveanum 
Golden Trumpet 
Gomphocarpus physocarpus, 
Gomphocarpus sinaicus 
Great Lakes Gentian 
Great Morinda 
Great Yellow Gentian 
Greater Periwinkle 
Green gentian 
Halenia major 
Hallab 
Hammerleaf Frangipani 
Heath bedstraw 
Hedge bedstraw 
Hemp Dogbane 
Herbaceous periwinkle 
Hot lips plant 
Hoya curtisii 
Hoya ignorata 
Hoya lacunosa 
Hoya lasiantha 
Hoya multiflora 
Hoya pubicalyx