Hedge Woundwort 
Helmet Skullcap 
Hemp Broomrape 
Henbit Deadnettle 
Hierba de la rabia 
Hierba vaquera 
Hoary mountainmint 
Hoary plantain 
Hoary skullcap 
Holly Mangrove 
Horehound 
Horned Bladderwort 
Horse Mint 
Humped Bladderwort 
Hygrophila auriculata 
Hypogomphia bucharica 
Hyssop 
Iboza 
Indian Broomrape 
Indian Catmint 
Indian warrior 
Italian Linaria 
Ivy Broomrape 
Ivy-leaved Toadflax