| Plant subtribes (Hu - Hy) | 
|  | 
| sandbox tree |  | Euphorbiaceae > Huroideae > Hureae |  | 
|  | 
| hyacinth |  | Hyacinthaceae > Hyacinthoideae > Hyacintheae |  | 
|  | 
|  |  | Euphorbiales > Euphorbiaceae > Hyaenanchoideae |  | 
|  | 
| chaulmoogra, hydnocarpus |  | Violales > Flacourtiineae > Flacourtiaceae |  | 
|  | 
| hydrocotyle, largeleaf pennywort, marshpennywort |  | Hydrocotylaceae > Hydrocotyloideae > Hydrocotyleae |  | 
|  | 
|  |  | Aranae > Arales > Araceae |  | 
|  | 
| cedro macho, hyeronima |  | Euphorbianae > Euphorbiales > Euphorbiaceae |  | 
|  | 
| hygrophila, starhorn, swampweed |  | Acanthineae > Acanthaceae > Hygrophileae |  | 
|  | 
|  |  | Violanae > Violales > Violaceae |  | 
|  | 
| filmy fern, ohiaku, palaihinahina, palailaulii |  | Hymenophyllaceae > Hymenophylloideae > Hymenophylleae |  | 
|  | 
|  |  | Lamianae > Lamiales > Orobanchaceae |  | 
|  | 
| henbane, stinking nightshade |  | Solanaceae > Hyoscyamoideae > Hyoscyameae |  | 
|  | 
|  |  | Asteraceae > Hyoseridoideae > Hyoserideae |  | 
|  | 
|  |  | Rubiales > Rubiineae > Rubiaceae |  | 
|  | 
| catsear |  | Asteraceae > Hypochaeridoideae > Hypochaerideae |  | 
|  | 
|  |  | Lamianae > Lamiales > Gesneriaceae |  | 
|  | 
| hairvein fern, hypoderris |  | Polypodiidae > Aspleniales > Tectariaceae |  | 
|  | 
| beadfern, bramblefern |  | Polypodiidae > Parkeriales > Dennstaedtiaceae |  | 
|  | 
|  |  | Cyperales > Cyperaceae > Hypolytreae |  | 
|  | 
| John Charles, bayamon, bee sage, bushmint, desert lavender, false ironwort, marubio, marubio oscuro, pignut |  | Lamiales > Lamiineae > Lamiaceae |  | 
|  | 
| European hyssop, hyssopus |  | Lamiineae > Lamiaceae > Hyssopeae |  |